document_title: List of NFL franchise post-season droughts

question_text: when was the last time the raiders went to the playoffs

text: Active team droughts[edit]

text: Post-season droughts[edit]

text: Updated through the 2016-17 post season.

text:
0^0
Longest drought in team history

0†0
Tied for Longest drought in team history

text:
Playoff Droughts [1][2]

0Team0
Last earned appearance in post-season
Seasons

Buffalo Bills ^
1999 AFC Wild Card Playoffs
17

Cleveland Browns ^
2002 AFC Wild Card Playoffs
14

Los Angeles Rams ^
2004 NFC Divisional Playoffs
12

Jacksonville Jaguars ^
2007 AFC Divisional Playoffs
9

Tampa Bay Buccaneers
2007 NFC Wild Card Playoffs
9

Tennessee Titans †
2008 AFC Divisional Playoffs
8

New York Jets
2010 AFC Championship Game
6

Chicago Bears
2010 NFC Championship Game
6

Philadelphia Eagles
2013 NFC Wild Card Playoffs
3

Los Angeles Chargers
2013 AFC Divisional Playoffs
3

New Orleans Saints
2013 NFC Divisional Playoffs
3

San Francisco 49ers
2013 NFC Championship Game
3

Baltimore Ravens
2014 AFC Divisional Playoffs
2

Indianapolis Colts
2014 AFC Championship Game
2

Cincinnati Bengals
2015 AFC Wild Card Playoffs
1

Minnesota Vikings
2015 NFC Wild Card Playoffs
1

Washington Redskins
2015 NFC Wild Card Playoffs
1

Arizona Cardinals
2015 NFC Championship Game
1

Denver Broncos
Super Bowl 50
1

Carolina Panthers
Super Bowl 50
1

2016 Playoff Teams

Miami Dolphins
2016 AFC Wild Card Playoffs
—

Oakland Raiders
2016 AFC Wild Card Playoffs
—

New York Giants
2016 NFC Wild Card Playoffs
—

Detroit Lions
2016 NFC Wild Card Playoffs
—

Kansas City Chiefs
2016 AFC Divisional Playoffs
—

Houston Texans
2016 AFC Divisional Playoffs
—

Dallas Cowboys
2016 NFC Divisional Playoffs
—

Seattle Seahawks
2016 NFC Divisional Playoffs
—

Pittsburgh Steelers
2016 AFC Championship Game
—

Green Bay Packers
2016 NFC Championship Game
—

New England Patriots
Super Bowl LI
—

Atlanta Falcons
Super Bowl LI
—

text: At 17 seasons, the Bills' playoff drought is also the longest in major North American professional sports.[3]

text: Playoff game victory droughts[edit]

text:
Updated through the 2016 season.
Sortable table, click on header arrows.

text:
0^0
Longest drought in team history

0†0
Tied for longest drought in team history

0♦0
Most consecutive losses in team history

0¤0
Tied for most consecutive losses in team history

0♣ ♣0
Most consecutive losses in NFL history

text:
Current Playoff Loss Streak[1]

Team
Last playoff game win
Seasons
Since Win
Loss
Streak
Playoff Losses - Teams

Cincinnati Bengals ^
1990 AFC Wild Card Playoffs
26
♦ 8
1990 Divisional - Los Angeles
2005 Wild Card - Pittsburgh
2009 Wild Card - New York Jets
2011 Wild Card - Houston
2012 Wild Card - Houston
2013 Wild Card - San Diego
2014 Wild Card - Indianapolis
2015 Wild Card - Pittsburgh

Detroit Lions
1991 NFC Divisional Playoffs*
25
♣ ♣ 9
1991 NFC Championship - Washington
1993 Wild Card - Green Bay
1994 Wild Card - Green Bay
1995 Wild Card - Philadelphia
1997 Wild Card - Tampa Bay
1999 Wild Card - Washington
2011 Wild Card - New Orleans
2014 Wild Card - Dallas
2016 Wild Card - Seattle

Buffalo Bills ^
1995 AFC Wild Card Playoffs
21
♦ 4
1995 Divisional - Pittsburgh
1996 Wild Card - Jacksonville
1998 Wild Card - Miami
1999 Wild Card - Tennessee

Cleveland Browns ^
1994 AFC Wild Card Playoffs
19**
2
1994 Divisional - Pittsburgh
2002 Wild Card - Pittsburgh

Miami Dolphins ^
2000 AFC Wild Card Playoffs
16
4 ¤
2000 Divisional - Oakland
2001 Wild Card - Baltimore
2008 Wild Card - Baltimore
2016 Wild Card - Pittsburgh

Oakland Raiders ^
2002 AFC Championship*
14
2 ¤
2002 Super Bowl - Tampa Bay
2016 Wild Card - Houston

Tampa Bay Buccaneers
Super Bowl XXXVII*
14
2
2005 Wild Card - Washington
2007 Wild Card - New York Giants

Tennessee Titans
2003 AFC Wild Card Playoffs
13
3 ¤
2003 Divisional - New England
2007 Wild Card - San Diego
2008 Divisional - Baltimore

Los Angeles Rams
2004 NFC Wild Card Playoffs
12
1
2004 Divisional - Atlanta

Washington Redskins
2005 NFC Wild Card Playoffs
11
4 ¤
2005 Divisional - Seattle
2007 Wild Card - Seattle
2012 Wild Card - Seattle
2015 Wild Card - Green Bay

Jacksonville Jaguars ^
2007 AFC Wild Card Playoffs
9
1
2007 Divisional - New England

Philadelphia Eagles
2008 NFC Divisional Playoffs
8
4
2008 NFC Championship - Arizona
2009 Wild Card - Dallas
2010 Wild Card - Green Bay
2013 Wild Card - New Orleans

Minnesota Vikings
2009 NFC Divisional Playoffs*
7
3
2009 NFC Championship - New Orleans
2012 Wild Card - Green Bay
2015 Wild Card - Seattle

New York Jets
2010 AFC Divisional Playoffs
6
1
2010 AFC Championship - Pittsburgh

Chicago Bears
2010 NFC Divisional Playoffs*
6
1
2010 NFC Championship - Green Bay

New York Giants
2011 !Super Bowl XLVI
5
1
2016 Wild Card - Green Bay

Los Angeles Chargers
2013 AFC Wild Card Playoffs
3
1
2013 Divisional - Denver

New Orleans Saints
2013 NFC Wild Card Playoffs
3
1
2013 Divisional - Seattle

San Francisco 49ers
2013 NFC Divisional Playoffs
3
1
2013 NFC Championship - Seattle

Baltimore Ravens
2014 AFC Wild Card Playoffs
2
1
2014 Divisional - New England

Dallas Cowboys
2014 NFC Wild Card Playoffs
2
2
2014 Divisional - Green Bay
2016 Divisional - Green Bay

Indianapolis Colts
2014 AFC Divisional Playoffs
2
1
2014 AFC Championship - New England

Kansas City Chiefs
2015 AFC Wild Card Playoffs
1
2
2015 Divisional - New England
2016 Divisional - Pittsburgh

Arizona Cardinals
2015 NFC Divisional Playoffs*
1
1
2015 NFC Championship - Carolina

Carolina Panthers
2015 NFC Championship*
1
1
2015 Super Bowl - Denver

Denver Broncos
Super Bowl 50*
1
0
3 game win streak

2016 Playoff0
Winners

Houston Texans
2016 AFC Wild Card Playoffs
—
1
2016 Divisional - New England

Seattle Seahawks
2016 NFC Wild Card Playoffs
—
1
2016 Divisional - Atlanta

Pittsburgh Steelers
2016 AFC Divisional Playoffs
—
1
2016 AFC Championship - New England

Green Bay Packers
2016 NFC Divisional Playoffs
—
1
2016 NFC Championship - Atlanta

Atlanta Falcons
2016 NFC Championship*
—
1
2016 Super Bowl - New England

New England Patriots
Super Bowl LI*
—
0
3 game win streak

Team
Last playoff game win
Seasons
Since Win
Loss
Streak
Playoff Losses - Teams

text:
(*): Franchise earned a bye in the Wild Card round.
(**): Franchise dormant 1996–1998.

text: AFC/NFC Championship game appearance droughts[edit]

text: This is also a list of the last time a particular club won a Divisional playoff game.

text:
Drought Reference [1]

Seasons
Team
Last appearance
in Conference Championship Game
Result

28
Cincinnati Bengals ^
1988 AFC
Won vs. Buffalo

25
Washington Redskins ^
1991 NFC
Won vs. Detroit

25
Detroit Lions ^
1991 NFC
Lost vs. Washington

24
Miami Dolphins ^
1992 AFC
Lost vs. Buffalo

24**
Cleveland Browns ^
1989 AFC
Lost vs. Denver

23
Buffalo Bills ^
1993 AFC
Won vs. Kansas City

23
Kansas City Chiefs †
1993 AFC
Lost vs. Buffalo

21
Dallas Cowboys ^
1995 NFC
Won vs. Green Bay

17
Jacksonville Jaguars ^
1999 AFC
Lost vs. Tennessee

15
Houston Texans ^
1985Never*
y —

15
Los Angeles Rams ^
2001 NFC
Won vs. Philadelphia

14
Tampa Bay Buccaneers
2002 NFC
Won vs. Philadelphia

14
Oakland Raiders ^
2002 AFC
Won vs. Tennessee

14
Tennessee Titans
2002 AFC
Lost vs. Oakland

9
Los Angeles Chargers
2007 AFC
Lost vs. New England

8
Philadelphia Eagles
2008 NFC
Lost vs. Arizona

7
New Orleans Saints
2009 NFC
Won vs. Minnesota

7
Minnesota Vikings
2009 NFC
Lost vs. New Orleans

6
New York Jets
2010 AFC
Lost vs. Pittsburgh

6
Chicago Bears
2010 NFC
Lost vs. Green Bay

5
New York Giants
2011 NFC
Won vs. San Francisco

4
Baltimore Ravens
2012 AFC
Won vs. New England

3
San Francisco 49ers
2013 NFC
Lost vs. Seattle

2
Indianapolis Colts
2014 AFC
Lost vs. New England

2
Seattle Seahawks
2014 NFC
Won vs. Green Bay

1
Denver Broncos
2015 AFC
Won vs. New England

1
Arizona Cardinals
2015 NFC
Lost vs. Carolina

1
Carolina Panthers
2015 NFC
Won vs. Arizona

.75
Z2016 Conference Finalists
2015
z

—
Pittsburgh Steelers
2016 AFC
Lost vs. New England

.5 —
New England Patriots
2016 AFC
Won vs. Pittsburgh

—
Green Bay Packers
2016 NFC
Lost vs. Atlanta

—
Atlanta Falcons
2016 NFC
Won vs. Green Bay

text:
(*): Franchise first played in 2002 season
(**): Franchise dormant 1996–1998.

text: Super Bowl or NFL Championship appearance droughts[edit]

text:
Last appearance in Super Bowl or
NFL Championship[1][4]

Seasons
Team
Last appearance
in Super Bowl
NFL
Season
Result

59
Detroit Lions
7003195700000000000♠ 1957 NFL Championship Game
1957
Won vs. Cleveland

48
New York Jets
7003196800000000000♠ Super Bowl III
1968
Won vs. Baltimore Colts

47
Kansas City Chiefs
7003196900000000000♠ Super Bowl IV
1969
Won vs. Minnesota

44*
Cleveland Browns*
7003196910000000000♠1969.1 1969 NFL Championship Game
1969
Lost vs. Minnesota

40
Minnesota Vikings
7003197700000000000♠ Super Bowl XI
1976
Lost vs. Oakland

32
Miami Dolphins
7003198400000000000♠ Super Bowl XIX
1984
Lost vs. San Francisco

28
Cincinnati Bengals
7003198800000000000♠ Super Bowl XXIII
1988
Lost vs. San Francisco

25
Washington Redskins
7003199100000000000♠ Super Bowl XXVI
1991
Won vs. Buffalo

23
Buffalo Bills
7003199300000000000♠ Super Bowl XXVIII
1993
Lost vs. Dallas

22
Jacksonville Jaguars
7000100000000000000♠ Never (enfranchised 1995)

Y —

22
Los Angeles Chargers
7003199400000000000♠ Super Bowl XXIX
1994
Lost vs. San Francisco

21
Dallas Cowboys
7003199500000000000♠ Super Bowl XXX
1995
Won vs. Pittsburgh

17
Tennessee Titans
7003199900000000000♠ Super Bowl XXXIV
1999
Lost vs. St. Louis Rams

15
Houston Texans
7000200000000000000♠ Never (enfranchised 2002)

Y —

15
Los Angeles Rams †
7003200100000000000♠ Super Bowl XXXVI
2001
Lost vs. New England

14
Tampa Bay Buccaneers
7003200200000000000♠ Super Bowl XXXVII
2002
Won vs. Oakland

14
Oakland Raiders
7003200210000000000♠ Super Bowl XXXVII
2002
Lost vs. Tampa Bay

12
Philadelphia Eagles
7003200400000000000♠ Super Bowl XXXIX
2004
Lost vs. New England

10
Chicago Bears
7003200600000000000♠ Super Bowl XLI
2006
Lost vs. Indianapolis

8
Arizona Cardinals
7003200800000000000♠ Super Bowl XLIII
2008
Lost vs. Pittsburgh

7
New Orleans Saints
7003200900000000000♠ Super Bowl XLIV
2009
Won vs. Indianapolis

7
Indianapolis Colts
7003200900000000000♠ Super Bowl XLIV
2009
Lost vs. New Orleans

6
Green Bay Packers
7003201000000000000♠ Super Bowl XLV
2010
Won vs. Pittsburgh

6
Pittsburgh Steelers
7003201010000000000♠ Super Bowl XLV
2010
Lost vs. Green Bay

5
New York Giants
7003201100000000000♠ Super Bowl XLVI
2011
Won vs. New England

4
Baltimore Ravens
7003201200000000000♠ Super Bowl XLVII
2012
Won vs. San Francisco

4
San Francisco 49ers
7003201210000000000♠ Super Bowl XLVII
2012
Lost vs. Baltimore Ravens

2
Seattle Seahawks
7003201420000000000♠ Super Bowl XLIX
2014
Lost vs. New England

1
Carolina Panthers
7003201500000000000♠ Super Bowl 50
2015
Lost vs. Denver

1
Denver Broncos
7003201500000000000♠ Super Bowl 50
2015
Won vs. Carolina

0
Atlanta Falcons
7003201600000000000♠ Super Bowl LI
2016
Lost vs. New England

0
New England Patriots
7003201600000000000♠ Super Bowl LI
2016
Won vs. Atlanta

text:
(*): Cleveland's drought does not include three seasons (1996–1998) where the franchise was dormant.
(†): Team was based in St. Louis.

text: Super Bowl win droughts[edit]

text: This list also counts all seasons since a team last won the league championship.

text:
Drought References[1][4]

Seasons
Team
Last Super Bowl crown
(1966–present)
NFL
Season
Last League Championship crown
Before 1970 Merger
(1920–1969)
Seasons

51
Arizona Cardinals[a]
Never
—
1947 NFL Championship
69

51
Detroit Lions
Never
—
1957 NFL Championship
59

51
Philadelphia Eagles
Never
—
1960 NFL Championship
56

51
Tennessee Titans[b]
Never
—
1961 AFL Championship
55

51
Los Angeles Chargers
Never
—
1963 AFL Championship
53

51
Buffalo Bills
Never
—
1965 AFL Championship
51

48
Cleveland Browns [d]
Never
—
1964 NFL Championship
49

51
Minnesota Vikings
Never
—
1969 NFL Championship[c]
47

51
Atlanta Falcons
Never (enfranchised 1966)
—

49
Cincinnati Bengals
Never (enfranchised 1968)
—

48
New York Jets[e]
Super Bowl III
1968

47
Kansas City Chiefs[e]
Super Bowl IV
1969

43
Miami Dolphins
Super Bowl VIII
1973

33
Oakland Raiders[f]
Super Bowl XVIII
1983

31
Chicago Bears
Super Bowl XX
1985

25
Washington Redskins
Super Bowl XXVI
1991

22
Jacksonville Jaguars
Never (enfranchised 1995)
—

22
Carolina Panthers
Never (enfranchised 1995)
—

22
San Francisco 49ers
Super Bowl XXIX
1994

21
Dallas Cowboys
Super Bowl XXX
1995

17
Los Angeles Rams[g]
Super Bowl XXXIV
1999

15
Houston Texans
Never (enfranchised 2002)
—

14
Tampa Bay Buccaneers
Super Bowl XXXVII
2002

10
Indianapolis Colts
Super Bowl XLI
2006

8
Pittsburgh Steelers
Super Bowl XLIII
2008

7
New Orleans Saints
Super Bowl XLIV
2009

6
Green Bay Packers
Super Bowl XLV
2010

5
New York Giants
Super Bowl XLVI
2011

4
Baltimore Ravens
Super Bowl XLVII
2012

3
Seattle Seahawks
Super Bowl XLVIII
2013

1
Denver Broncos
Super Bowl 50
2015

0
New England Patriots
Super Bowl LI
2016

text:
a Team won as the Chicago Cardinals in 1947.
b Team won as the Houston Oilers in 1961.
c AFL and NFL league champions met in Super Bowls I thru IV before the 1970 merger (1966–1969). They are not generally counted in the overall league championship list.
d Cleveland's drought does not include three seasons (1996–98) when the franchise was dormant.
e Super Bowl winner was not the NFL league champion till after 1970 merger (Super Bowl V).
f Team was based in Los Angeles when it won Super Bowl XVIII.
g Team was based in St. Louis when it won Super Bowl XXXIV.

text: Super Bowl crown droughts by division[edit]

text:
Division
Last Super Bowl crown
Seasons

AFC South
XLI — Colts
10

NFC South
XLIV — Saints
7

NFC North
XLV — Packers
6

NFC East
XLVI — Giants
5

AFC North
XLVII — Ravens
4

NFC West
XLVIII — Seahawks
3

AFC West
50 — Broncos
1

AFC East
LI — Patriots
0

text: Cities/regions awaiting first Super Bowl crown[edit]

text: Listed according to seasons waited. Current NFL cities/regions only

text:
Last city to leave list - Seattle, 2013 season

City/region
Seasons waited
Conference Title(s)
Team(s)
Notes

Detroit
51
None
Detroit Lions (1966–)
Played in the 1991 NFC Championship Game

Philadelphia
51
1980, 2004
Philadelphia Eagles (1966–)
Played in Super Bowls XV and XXXIX

Buffalo
51
1990, 1991, 1992, 1993
Buffalo Bills (1966–)
Played in Super Bowls XXV, XXVI, XXVII, and XXVIII

Atlanta
51
1998, 2016
Atlanta Falcons (1966–)
Played in Super Bowls XXXIII and LI

Minneapolis–St. Paul
51
1969, 1973, 1974, 1976
Minnesota Vikings (1966–)
Played in Super Bowls IV, VIII, IX, and XI

Cincinnati
49
1981, 1988
Cincinnati Bengals (1968–)
Played in Super Bowls XVI and XXIII

Cleveland
48
None
Cleveland Browns (1966–)
Played in the 1986, 1987, and 1989 AFC Championship Games

Houston
46
None
Includes 31 Oilers seasons (1966–1996) and 15 Texans seasons (2002–)
Played in the 1978 and 1979 AFC Championship Games

Phoenix
29
2008
Phoenix/Arizona Cardinals (1988–)
Played in Super Bowl XLIII

Jacksonville
22
None
Jacksonville Jaguars (1995–)
Played in the 1996 and 1999 AFC Championship Games

Charlotte
22
2003, 2015
Carolina Panthers (1995–)
Played in Super Bowls XXXVIII and 50

Nashville
20
1999
Tennessee Oilers/Titans (1997–)
Played in Super Bowl XXXIV

text: Division title droughts[edit]

text: Listed according to seasons waited. Updated through the 2016 season.

text:
Franchise
0 0 Most recent0 0
division title
0Year0
Seasons

Cleveland Browns^
AFC Central
1989
24**

Detroit Lions^
NFC Central
1993
23

Buffalo Bills^
AFC East
1995
21

Jacksonville Jaguars^
AFC Central
1999
17

Oakland Raiders^
AFC West
2002
14

New York Jets
AFC East
2002
14

Los Angeles Rams†
NFC West
2003
13

Tampa Bay Buccaneers
NFC South
2007
9

Miami Dolphins^
AFC East
2008
8

Tennessee Titans
AFC South
2008
8

Los Angeles Chargers
AFC West
2009
7

Chicago Bears
NFC North
2010
6

New York Giants
NFC East
2011
5

New Orleans Saints
NFC South
2011
5

Baltimore Ravens
AFC North
2012
4

San Francisco 49ers
NFC West
2012
4

Philadelphia Eagles
NFC East
2013
3

Indianapolis Colts
AFC South
2014
2

Cincinnati Bengals
AFC North
2015
1

Denver Broncos
AFC West
2015
1

Washington Redskins
NFC East
2015
1

Minnesota Vikings
NFC North
2015
1

Carolina Panthers
NFC South
2015
1

Arizona Cardinals
NFC West
2015
1

2016 Division Champions

New England Patriots
AFC East
2016
—

Pittsburgh Steelers
AFC North
2016
—

Houston Texans
AFC South
2016
—

Kansas City Chiefs
AFC West
2016
—

Dallas Cowboys
NFC East
2016
—

Green Bay Packers
NFC North
2016
—

Atlanta Falcons
NFC South
2016
—

Seattle Seahawks
NFC West
2016
—

text: **Does not include the three seasons (1996–1998) during which the franchise suspended operations.

text: Historical team droughts[edit]

text: Playoff droughts of 5 plus seasons[edit]

text:
0^0
Denotes active streak

text:
Last place NFL finishes
Last place AFL finishes (1960–1969)

text:
List of Droughts[1]

Seasons
Team
Drought Duration
Division or Conference Last Place
finishes during drought
League Worst win-loss record
during drought

Last Place
Seasons

7001250000000000000♠25
Washington Redskins A !Washington Redskins
1946–1970
4
1950, 1952, 1960–1961
1961

7001250000000000000♠25
Arizona Cardinals A !Chicago / St. Louis Cardinals
1949–1973
5
1951, 1953–1954, 1957, 1959
1953, 1954, 1957 tie, 19591959 tie

7001240000000000000♠24
Pittsburgh Steelers A !Pittsburgh Steelers
1948–1971
5
1955, 1965, 1967–1969
1965, 1969 tie

7001200000000000000♠20
New Orleans Saints A !New Orleans Saints
1967–1986
9
1967, 1970–1972, 1975, 1977, 1980–1981, 1986
19751975 tie, 1980

7001170000000000000♠17
Denver Broncos A !Denver Broncos
1960–1976
8
1960, 1963–1967, 1970–1971
1960, 1963, 1964, 1965 tie, 1967

7001170000000000000♠17
Philadelphia Eagles A !Philadelphia Eagles
1961–1977
7
1962–1963, 1968–1970, 1972, 1975
1968 tie

7001170000000000000♠17
New York Giants D !New York Giants
1964–1980
9
1964, 1966, 1971, 1973–1974, 1976–1978, 1980
1964, 1966, 1974 tie

7001170000000000000♠17 ^
Buffalo Bills A !Buffalo Bills
2000–2016
8
2001–2002, 2008–2013
—

7001160000000000000♠16
Detroit Lions A !Detroit Lions
1936–1951
4
1942, 1946–1948
1942, 1946, 1948

7001150000000000000♠15
Arizona Cardinals B !Chicago Cardinals
1932–1946
10
1933, 1935–1936, 1938–1940, 1943–1946
1933, 1938 tie, 1939, 1943, 1944 tie[a], 1945

7001150000000000000♠15
Green Bay Packers A !Green Bay Packers
1945–1959
4
1949, 1953, 1957, 1958
1957 tie, 1958

7001150000000000000♠15
Arizona Cardinals C !St. Louis / Phoenix / Arizona Cardinals
1983–1997
7
1985–1986, 1990–1992, 1995, 1997
—

7001140000000000000♠14
Pittsburgh Steelers B !Pittsburgh Pirates / Steelers
1933–1946
7
1933–1934, 1938–1939, 1941, 1944–1945
1938 tie, 1941, 1944 tie[a]

7001140000000000000♠14
Philadelphia Eagles B !Philadelphia Eagles
1933–1946
5
1935–1937, 1940, 1942
1935, 1936, 1940

7001140000000000000♠14
Kansas City Chiefs A !Kansas City Chiefs
1972–1985
5
1977–1979, 1983, 1985
19771977 tie

7001140000000000000♠14
Tampa Bay Buccaneers A !Tampa Bay Buccaneers
1983–1996
8
1983, 1985–1986, 1989, 1991, 1993–1995
19831983 tie, 1985 tie, 1986

7001140000000000000♠14
Cincinnati Bengals A !Cincinnati Bengals
1991–2004
6
1991–1993, 1998, 2001–2002
1993, 1998 tie, 2002

7001140000000000000♠14 ^
Cleveland Browns A !Cleveland Browns
2003–2016
12
2003–2006, 2008–2009, 2011–2016
2015 tie, 2016

7001130000000000000♠13
Chicago Bears A !Chicago Bears
1964–1976
5
1969–1970, 1972–1974
1969 tie

7001130000000000000♠13
San Diego Chargers A !San Diego Chargers
1966–1978
3
1972–1973, 1975
1975 tie

7001130000000000000♠13
Oakland Raiders A !Oakland Raiders
2003–2015
6
2004–2007, 2013–2014
2003 tie, 2006

7001120000000000000♠12
Detroit Lions B !Detroit Lions
1958–1969
2
1966, 1968
—

7001120000000000000♠12
San Francisco 49ers A !San Francisco 49ers
1958–1969
3
1963–1964, 1969
1963

7001120000000000000♠12
New England Patriots A !Boston / New England Patriots
1964–1975
4
1967, 1970, 1972, 1975
1970

7001120000000000000♠12
Atlanta Falcons A !Atlanta Falcons
1966–1977
3
1967–1968, 1974
1967, 1968 tie

7001120000000000000♠12 ^
Los Angeles Rams A !St. Louis / Los Angeles Rams
2005–2016
6
2007–2009, 2011, 2013–2014
2009, 2011 tie

7001110000000000000♠11
Los Angeles Rams B !Los Angeles Rams
1956–1966
4
1956, 1959, 1962, 1965
19591959 tie, 1962

7001110000000000000♠11
New York Jets A !New York Jets
1970–1980
1
1980
—

7001110000000000000♠11
Detroit Lions C !Detroit Lions
1971–1981
1
1979
19791979 tie

7001110000000000000♠11
Detroit Lions D !Detroit Lions
2000–2010
6
2001–2003, 2006, 2008–2009
2008

7001100000000000000♠10
Philadelphia Eagles C !Philadelphia Eagles
1950–1959
2
1956, 1958
1956

7001100000000000000♠10
Green Bay Packers B !Green Bay Packers
1983–1992
1
1988
—

7001100000000000000♠10
Seattle Seahawks A !Seattle Seahawks
1989–1998
4
1992–1994, 1996
1992 tie

7000900000000000000♠9
Green Bay Packers C !Green Bay Packers
1973–1981
2
1976, 1980
—

7000900000000000000♠9
Indianapolis Colts A !Baltimore / Indianapolis Colts
1978–1986
4
1978 - 1979, 1982, 1986
1981 tie, 1982

7000900000000000000♠9
San Diego Chargers B !San Diego Chargers
1983–1991
4
1984, 1986, 1989, 1991
—

7000900000000000000♠9
Los Angeles Rams C !Los Angeles / St. Louis Rams
1990–1998
6
1991–1994, 1997–1998
—

7000900000000000000♠9
Arizona Cardinals E !Arizona Cardinals
1999–2007
4
2000, 2002–2003, 2006
2003 tie

7000900000000000000♠9
Houston Texans A !Houston Texans
2002–2010
5
2002–2003, 2005–2007
2005

7000900000000000000♠9 ^
Tampa Bay Buccaneers B !Tampa Bay Buccaneers
2008–2016
6
2009, 2011–2015
20142014 tie

7000900000000000000♠9 ^
Jacksonville Jaguars A !Jacksonville Jaguars
2008–2016
4
2008–2009, 2012, 2016
2012 tie

7000800000000000000♠8
New York Jets B !New York Titans / Jets
1960–1967
2
1962–1963
—

7000800000000000000♠8
Tennessee Titans A !Houston Oilers
1970–1977
4
1970, 1972–1973, 1976
1972, 1973

7000800000000000000♠8
San Francisco 49ers B !San Francisco 49ers
1973–1980
2
1978–1979
1978, 1979 tie

7000800000000000000♠8
Atlanta Falcons B !Atlanta Falcons
1983–1990
7
1983–1985, 1987–1990
1987

7000800000000000000♠8
San Diego Chargers C !San Diego Chargers
1996–2003
5
1997–1998, 2000–2001, 2003
2000, 2003 tie

7000800000000000000♠8
San Francisco 49ers C !San Francisco 49ers
2003–2010
2
2004–2005
2004

7000800000000000000♠8 ^
Tennessee Titans B !Tennessee Titans
2009–2016
3
2010, 2014–2015
20142014 tie, 2015 tie

7000700000000000000♠7
Los Angeles Rams D !Cleveland Rams
1937–1944 [b]
2
1937, 1941
1937

7000700000000000000♠7
San Francisco 49ers D !San Francisco 49ers
1950–1956
0
—
—

7000700000000000000♠7
Oakland Raiders B !Oakland Raiders
1960–1966
2
1961–1962
1961, 1962

7000700000000000000♠7
Minnesota Vikings A !Minnesota Vikings
1961–1967
3
1961, 1966–1967
—

7000700000000000000♠7
Buffalo Bills B !Buffalo Bills
1967–1973
2
1968, 1971

1968
1971

7000700000000000000♠7
Cleveland Browns B !Cleveland Browns
1973–1979
3
1974–1975, 1977
—

7000700000000000000♠7
Seattle Seahawks B !Seattle Seahawks
1976–1982
3
1976, 1980–1981
—

7000700000000000000♠7
Detroit Lions E !Detroit Lions
1984–1990
1
1987
—

7000700000000000000♠7
New England Patriots A !New England Patriots
1987–1993
2
1990, 1992
1990, 1992 tie

7000700000000000000♠7
Indianapolis Colts B !Indianapolis Colts
1988–1994
2
1991, 1993
1991

7000700000000000000♠7
New Orleans Saints B !New Orleans Saints
1993–1999
3
1995–1996, 1999
—

7000700000000000000♠7
Miami Dolphins A !Miami Dolphins
2009–2015
1
2015
—

7000600000000000000♠6
Chicago Bears B !Chicago Bears
1957–1962
0
—
—

7000600000000000000♠6
Dallas Cowboys A !Dallas Cowboys
1960–1965
1
1960
1960

7000600000000000000♠6
Arizona Cardinals E !St. Louis Cardinals
1976–1981
2
1979, 1981
—

7000600000000000000♠6
Tennessee Titans C !Houston Oilers
1981–1986
4
1983–1986
19831983 tie

7000600000000000000♠6
Buffalo Bills C !Buffalo Bills
1982–1987
2
1984–1985
1984, 1985 tie

7000600000000000000♠6
Philadelphia Eagles D !Philadelphia Eagles
1982–1987
1
1984
—

7000600000000000000♠6
New York Jets C !New York Jets
1992–1997
3
1994–1996
1995, 1996

7000600000000000000♠6
Washington Redskins B !Washington Redskins
1993–1998
2
1993–1994
—

7000600000000000000♠6
Oakland Raiders C !Los Angeles / Oakland Raiders
1994–1999
0
—
—

7000600000000000000♠6
Chicago Bears C !Chicago Bears
1995–2000
4
1997–2000
—

7000600000000000000♠6
Carolina Panthers A !Carolina Panthers
1997–2002
2
2001–2002
2001

7000600000000000000♠6
Miami Dolphins B !Miami Dolphins
2002–2007
3
2004, 2006–2007
2007

7000600000000000000♠6 ^
New York Jets D !New York Jets
2011–2016
2
2014, 2016
—

7000600000000000000♠6 ^
Chicago Bears E !Chicago Bears
2011–2016
3
2014–2016
—

7000500000000000000♠5
New York Giants D !New York Giants
1951–1955
0
—
—

7000500000000000000♠5
Chicago Bears D !Chicago Bears
1951–1955
0
—
—

7000500000000000000♠5
Indianapolis Colts C !Baltimore Colts
1953–1957
1
1954
—

7000500000000000000♠5
Cleveland Browns C !Cleveland Browns
1959–1963
0
—
—

7000500000000000000♠5
Buffalo Bills D !Buffalo Bills
1975–1979
2
1976–1977
—

7000500000000000000♠5
Cincinnati Bengals B !Cincinnati Bengals
1976–1980
3
1978–1980
—

7000500000000000000♠5
Washington Redskins C !Washington Redskins
1977–1981
0
—
—

7000500000000000000♠5
Cincinnati Bengals C !Cincinnati Bengals
1983–1987
1
1987
—

7000500000000000000♠5
Dallas Cowboys B !Dallas Cowboys
1986–1990
2
1988, 1989
1988, 1989

7000500000000000000♠5
Tennessee Titans D !Houston / Tennessee Oilers
1994–1998
1
1994
1994

7000500000000000000♠5
Kansas City Chiefs B !Kansas City Chiefs
1998–2002
1
2002
—

7000500000000000000♠5
Washington Redskins D !Washington Redskins
2000–2004
1
2004
—

7000500000000000000♠5
Jacksonville Jaguars B !Jacksonville Jaguars
2000–2004
0
—
—

7000500000000000000♠5
New Orleans Saints C !New Orleans Saints
2001–2005
1
2005
—

7000500000000000000♠5
Denver Broncos B !Denver Broncos
2006–2010
1
2010
—

Seasons
Team
Drought Duration
Last Place
Seasons
League Worst win-loss record
during drought

Division or Conference Last Place
finishes during drought

text: Most consecutive post-season losses in team history[edit]

text: This is a sortable table of all 32 current NFL teams. Ten teams have multiple losing streaks where they lost an equal number of post season games before breaking the drought.

text: Updated through the 2016 regular season.

text:
0^0
Denotes active drought

text:
Team
Streak lasted
Last win
Games Lost
Playoff Losses
Score
Opponent
Next win

Arizona Cardinals
7001510000000000000♠ 51 years
1947
Championship
4.1 !4
1948 NFL Champ.
1974 Div.
1975 Div.
1982 1st Round
-1 !0–7
14–30
23–35
16–41
Eagles
Vikings
Rams
Packers
1998 Wild Card

Atlanta Falcons
7000800000000000000♠ 8 years
2004 Divisional
4.2 !4
2004 NFC Champ.
2008 Wild Card
2010 Div.
2011 Wild Card
10–27
24–30
21–48
2–24
Eagles
Cardinals
Packers
Giants
2012 Divisional

Baltimore Ravens
7000700000000000000♠ 7 years
2001
Wild Card
3.1 !3
2001 Div.
2003 Wild Card
2006 Div.
10–27
17–20
6–15
Steelers
Titans
Colts
2008 Wild Card

Buffalo Bills^
7001210000000000000♠ 21 years
1995
Div !1995
Wild Card
4.3 !4
1995 Div.
1996 Wild Card
1998 Wild Card
1999 Wild Card
21–40
27–30
17–24
16–22
Steelers
Jaguars
Dolphins
Titans
TBD

Carolina Panthers
7000800000000000000♠ 8 years
2005
Divisional
3
2005 NFC Champ.
2008 Div.
2013 Div.
14–34
13–33
10–23
Seahawks
Cardinals
49ers
2014 Div !2014 Wild Card

Chicago Bears
7001120000000000000♠ 12 years
1994
AF !1994
Wild Card
3.2 !3
1994 Div.
2001 Div.
2005 Div.
15–44
19–33
21–29
49ers
Eagles
Panthers
2006 Divisional

Cincinnati Bengals^
7001260000000000000♠ 26 years
1990 Div !1990
Wild Card
8
1990 Div.
2005 Wild Card
2009 Wild Card
2011 Wild Card
2012 Wild Card
2013 Wild Card
2014 Wild Card
2015 Wild Card
10–20
17–31
14–24
10–31
13–19
10–27
10–26
16–18
Raiders
Steelers
Jets
Texans
Texans
Chargers
Colts
Steelers
TBD

Cleveland Browns
7001170000000000000♠ 17 years
1969 Divisional
6
1969 NFL Champ.
1971 Div.
1972 Div.
1980 Div.
1982 1st Round
1985 Div.
7–27
3–20
14–20
12–14
10–27
21–24
Vikings
Colts
Dolphins
Raiders
Raiders
Dolphins
1986 Divisional

Dallas Cowboys
7001130000000000000♠ 13 years
1996
Div !1996
Wild Card
6.2 !6
1996 Div.
1998 Wild Card
1999 Wild Card
2003 Wild Card
2006 Wild Card
2007 Div.
17–26
7–20
10–27
10–29
20–21
17–21
Panthers
Cardinals
Vikings
Panthers
Seahawks
Giants
2009 Wild Card

Denver Broncos
7000900000000000000♠ 9 years
1977
Conference
Championship
5.1 !5
1977 !Super Bowl XII
1978 Div.
1979 Wild Card
1983 Wild Card
1984 Div.
10–27
10–33
7–13
7–31
17–24
Cowboys
Steelers
Oilers
Seahawks
Steelers
1986 Divisional

Detroit Lions^
7001250000000000000♠ 25 years
1991
Divisional
9
1991.2 !1991 NFC Champ.
1993 Wild Card
1994 Wild Card
1995 Wild Card
1997 Wild Card
1999 Wild Card
2011 Wild Card
2014 Wild Card
2016 Wild Card
10–41
24–28
12–16
37–58
10–20
13–27
28–45
20–24
6-26
Redskins
Packers
Packers
Eagles
Buccaneers
Redskins
Saints
Cowboys
Seahawks
TBD

Green Bay Packers
005 (2 loss) streaks
7000400000000000000♠ 4 years
1997 Conference
Championship
2.2 !2
1997.2 !Super Bowl XXXII
1998 Wild Card
24–31
27–30
Broncos
49ers
2001 Wild Card

7000200000000000000♠ 2 years
2001
Wild Card
2.3 !2
2001.1 !2001 Div.
2002 Wild Card
17–45
7–27
Rams
Falcons
2003 Wild Card

7000400000000000000♠ 4 years
2003
Wild Card
2.4 !2
2003.1 !2003 Div.
2004 Wild Card
17–20 (OT)
17–31
Eagles
Vikings
2007 Divisional

7000300000000000000♠ 3 years
2007
Divisional
2.5 !2
2007.2 !2007 NFC Champ.
2009 Wild Card
20–23 (OT)
45–51 (OT)
Giants
Cardinals
2010 Wild Card

7000200000000000000♠ 2 years
2012
Wild Card
2.6 !2
2012 Div.
2013 Wild Card
31–45
20–23
49ers
49ers
2014 Divisional

Houston Texans
7000400000000000000♠ 4 years
2012 Wild Card
2
2012.1 !2012 Divisional
2015 Wild Card
28–41
0–30
Patriots
Chiefs
2016 Wild Card

Indianapolis Colts
002 (5 loss) streaks
7001240000000000000♠24 years
1971
Divisional
5.2 !5
1971.1 !1971 AFC Champ.
1975 Div.
1976 Div.
1977 Div.
1987 Div.
0–21
10–28
14–40
31–37 (2 OT)
21–38
Dolphins
Steelers
Steelers
Raiders
Browns
1995 Wild Card

7000800000000000000♠ 8 years
1995
Divisional
5.3 !5
1995.3 !1995 AFC Champ.
1996 Wild Card
1999 Div.
2000 Wild Card
2002 Wild Card
16–20
14–42
16–19
17–23 (OT)
0–41
Steelers
Steelers
Titans
Dolphins
Jets
2003 Wild Card

Jacksonville Jaguars
002 (2 loss) streaks
2 years
1996
Divisional
2.6 !2
1996.2 !1996 AFC Champ.
1997 Wild Card
6–20
17–42
Patriots
Broncos
1998 Wild Card

7000800000000000000♠ 8 years
1999
Divisional
2.7 !2
1999.2 !1999 AFC Champ.
2005 Wild Card
14–33
3–28
Titans
Patriots
2007 Div !2007 Wild Card

Kansas City Chiefs
7001210000000000000♠ 21 years
1993
Divisional
8
1993.2 !1993 AFC Champ.
1994 Wild Card
1995 Div.
1997 Div.
2003 Div.
2006 Wild Card
2010 Wild Card
2013 Wild Card
13–30
17–27
7–10
10–14
31–38
8–23
7–30
44–45
Bills
Dolphins
Colts
Broncos
Colts
Colts
Ravens
Colts
2015 Wild Card

Los Angeles Chargers
7001130000000000000♠ 13 years
1994
AFC Championship
4.8 !4
1994.2 !Super Bowl XXIX
1995 Wild Card
2004 Wild Card
2006 Div.
26–49
20–35
17–20 (OT)
21–24
49ers
Colts
Jets
Patriots
2007 Div !2007 Wild Card

Los Angeles Rams
7001230000000000000♠ 23 years
1951
Championship
5.5 !5
1952 Nat. Conf.
1955 NFL Champ.
1967 NFL W Conf.
1969 NFL W Conf.
1973 Div.
21–31
14–38
7–28
20–23
16–27
Lions
Browns
Packers
Vikings
Cowboys
1974 Divisional

Miami Dolphins
002 (4 loss) streaks
7000900000000000000♠ 9 years
1973
Super Bowl
4.5 !4
1974 Div.
1978 Wild Card
1979 Div.
1981 Div.
26–28
9–17
14–34
38–41 (OT)
Raiders
Oilers
Steelers
Chargers
1982 First Round

7001160000000000000♠ 16 years
2000
Wild Card
4.9 !4
2000 Div.
2001 Wild Card
2008 Wild Card
2016 Wild Card
0–27
3–20
9–27
12–30
Raiders
Ravens
Ravens
Steelers
TBD

Minnesota Vikings
7000900000000000000♠ 9 years
1988
Wild Card
6.3 !6
1988 Div.
1989 Div.
1992 Wild Card
1993 Wild Card
1994 Wild Card
1996 Wild Card
9–34
13–41
7–24
10–17
18–35
15–45
49ers
49ers
Redskins
Giants
Bears
Cowboys
1997 Wild Card

New England Patriots
7001220000000000000♠ 22 years
1963
Divisional
4.6 !4
1963 AFL Champ.
1976 Div.
1978 Div.
1982 1st Round
10–51
21–24
14–31
13–28
Chargers
Raiders
Oilers
Dolphins
1985 Wild Card

New Orleans Saints
7001320000000000000♠ 32 years
1967 Enfranchised
No Playoff
Wins
till 2000
4.7 !4
1987 Wild Card
1990 Wild Card
1991 Wild Card
1992 Wild Card
10–44
6–16
20–27
20–36
Vikings
Bears
Falcons
Eagles
2000 Wild Card

New York Giants
7001180000000000000♠ 18 years
1938
Championship
6.4 !6
1939 NFL Champ.
1941 NFL Champ.
1943 East Div.
1944 NFL Champ.
1946 NFL Champ.
1950 Am. Conf.
0–27
9–37
0–28
7–14
14–24
3–8
Packers
Bears
Redskins
Packers
Bears
Browns
1956 Championship

New York Jets
005 (2 loss) streaks
7001140000000000000♠ 14 years
1968
Super Bowl III
2.8 !2
1969 AFL Div.
1981 Wild Card
6–13
27–31
Chiefs
Bills
1982 First Round

7000400000000000000♠ 4 years
1982 2nd Round
2.9 !2
1982.1 !1982 AFC Champ.
1985 Wild Card
0–14
14–26
Dolphins
Patriots
1986 Wild Card

7001120000000000000♠ 12 years
1986 Wild Card
2.91 !2
1986 Div.
1991 Wild Card
20–23 (2 OT)
10–17
Browns
Oilers
1998 World !1998 Divisional

7000400000000000000♠ 4 years
1998 Divisional
2.92 !2
1998.1 !1998 AFC Champ.
2001 Wild Card
10–23
24–38
Broncos
Raiders
2002 Div !2002 Wild Card

7000500000000000000♠ 5 years
2004
Wild Card
2.93 !2
2004.1 !2004 Divisional
2006 Wild Card
17–20 (OT)
16–37
Steelers
Patriots
2009 Wild Card

Oakland Raiders
004 (2 loss) streaks
7000300000000000000♠ 3 years
1970
Divisional
2.94 !2
1970 AFC Champ.
1972 Div.
17–27
7–13
Colts
Steelers
1973 Divisional

7000700000000000000♠ 7 years
1983
Super Bowl XVIII
2.95 !2
1984 Wild Card
1985 Div.
7–13
20–27
Seahawks
Patriots
1990 Divisional

7000300000000000000♠ 3 years
1990 Divisional
2.96 !2
1990.2 !1990 AFC Champ.
1991 Wild Card
3–51
6–10
Bills
Chiefs
1993 Wild Card

7001140000000000000♠ 14 years
2002 AFC Championship
2.96 !2
1990.2 !Super Bowl XXXVIII
2016 Wild Card
24-41
14-27
Bucs
Texans
TBD

Philadelphia Eagles
7001120000000000000♠ 12 years
1980
Conference
Championship
5.4 !5
1980.1 !Super Bowl XV
1981 Wild Card
1988 Div.
1989 Wild Card
1990 Wild Card
10–27
21–27
12–20
7–21
6–20
Raiders
Giants
Bears
Rams
Redskins
1992 Wild Card

Pittsburgh Steelers
002 (3 loss) streaks
7000500000000000000♠ 5 years
1989
Wild Card
3.3 !3
1989.1 !1989 Div.
1992 Div.
1993 Wild Card
23–24
3–24
24–27
Broncos
Bills
Chiefs
1994 Divisional

7000400000000000000♠4 years
2010 AFC Championship
3
2010.1 !Super Bowl XLV
2011 Wild Card
2014 Wild Card
25–31
23–29
17–30
Packers
Broncos
Ravens
2015 Wild Card

San Francisco 49ers
7000400000000000000♠4 years
1984
Super Bowl XIX
3.4 !3
1985 Wild Card
1986 Div.
1987 Div.
3–17
3–49
24–36
Giants
Giants
Vikings
1988 Divisional

Seattle Seahawks
7001210000000000000♠ 21 years
1984
Su !1984
Wild Card
6.5 !6
1984.2 !1984 Div.
1987 Wild Card
1988 Div.
1999 Wild Card
2003 Wild Card
2004 Wild Card
10–31
20–23 (OT)
13–21
17–20
27–33 (OT)
20–27
Dolphins
Oilers
Bengals
Dolphins
Packers
Rams
2005 Divisional

Tampa Bay Buccaneers
002 (3 loss) streaks
7001180000000000000♠ 18 years
1979
Divisional
3.5 !3
1979.2 !1979 NFC Champ.
1981 Div.
1982 1st Round
0–9
0–38
17–30
Rams
Cowboys
Cowboys
1997 Wild Card

7000300000000000000♠3 years
1999
Divisional
3.6 !3
1999.3 !1999 NFC Champ.
2000 Wild Card
2001 Wild Card
6–11
3–21
9–31
Rams
Eagles
Eagles
2002 Divisional

Tennessee Titans^
004 (3 loss) streaks
7001170000000000000♠ 17 years
1961 AFL
Championship
3.7 !3[Hou]
1962 AFL Champ.
1967 AFL Champ.
1969 AFL Div.
17–20 (2 OT)
7–40
7–56
Chief !Dallas Texans
Raiders
Raiders
1978 Wild Card

7000300000000000000♠ 3 years
1988
Wild Card
3.8 !3[Hou]
1988 Div.
1989 Wild Card
1990 Wild Card
10–17
23–26 (OT)
14–41
Bills
Steelers
Bengals
1991
Wild Card

7000800000000000000♠ 8 years
1991
Div !1991
Wild Card
3.9 !3[Hou]
1991.1 !1991 Divisional
1992 Wild Card
1993 Divisional
24–26
38–41 (OT)
20–28
Broncos
Bills
Chiefs
1999
Wild Card

7001130000000000000♠ 13 years
2003
Wild Card
3.91 !3
2003.3 !2003 Div.
2007 Wild Card
2008 Div.
14–17
6–17
10–13
Patriots
Chargers
Ravens
TBD

Washington Redskins
002 (4 loss) streaks
7001100000000000000♠ 10 years
1972
NFC Championship
4.9 !4
1972.2 !Super Bowl VII
1973 Div.
1974 Div.
1976 Div.
7–14
20–27
10–19
20–35
Dolphins
Vikings
Rams
Vikings
1982 First Round

7001110000000000000♠ 11 years
2005
Wild Card
4.9 !4
2005 Div.
2007 Wild Card
2012 Wild Card
2015 Wild Card
10–20
14–35
14–24
18–35
Seahawks
Seahawks
Seahawks
Packers
TBD

Team
Streak lasted
Last win
Games Lost
Playoff Games
Score
Opponent
Next win

text: Hou These three streaks occurred when the team was known as the Houston Oilers.

text: Longest post-season droughts in team history[edit]

text:
Updated through the 2016 season.
Note that the NFL did not institute a permanent playoff tournament until 1967 and that the NFL Championship Game and any impromptu one-game playoffs (played only in the event of a tie atop the division standings) were the only postseason matchups in this era (the Bert Bell Benefit Bowl is considered an exhibition game for the purpose of this list).

text:
0^0
Denotes active streak

text:
No post season appearances

Team
Longest streak with
no post-season appearances
Seasons

Washington Redskins
1946–1970
25

Arizona Cardinals
1949–1973
25

Pittsburgh Steelers
1948–1971
24

New Orleans Saints
1967–1986
20

Denver Broncos
1960–1976
17

Philadelphia Eagles
1961–1977
17

New York Giants
1964–1980
17

Buffalo Bills^
2000–2016^
17

Detroit Lions
1936–1951
16

Green Bay Packers
1945–1959
15

Kansas City Chiefs
1972–1985
14

Tampa Bay Buccaneers
1983–1996
14

Cincinnati Bengals
1991–2004
14

Cleveland Browns^
2003–2016^
14

Chicago Bears
1964–1976
13

Los Angeles Chargers
1966–1978
13

Oakland Raiders
2003–2015
13

San Francisco 49ers
1958–1969
12

New England Patriots
1964–1975
12

Atlanta Falcons
1966–1977
12

Los Angeles Rams^
2005–2016^
12

New York Jets
1970–1980
11

Seattle Seahawks
1989–1998
10

Indianapolis Colts
1978–1986
9

Houston Texans
2002–2010
9

Jacksonville Jaguars^
2008–2016^
9

Tennessee Titans
1970–1977
8

Minnesota Vikings
1961–1967
7

Miami Dolphins
2009–2015
7

Dallas Cowboys
1960–1965
6

Carolina Panthers
1997–2002
6

Baltimore Ravens
1996–1999
4

Team
Longest streak with
no post-season appearances
Seasons

No post season victories

Team
Longest streak with
no post-season victories
Seasons

Arizona Cardinals
1948–1997
50

Pittsburgh Steelers
1933–1971
39

Detroit Lions
1958–1990
33

New Orleans Saints
1967–1999
33

Washington Redskins
1944–1971
28

Cincinnati Bengals^
1991–2016^
26

Indianapolis Colts
1972–1994
23

Los Angeles Rams
1952–1973
22

New York Giants
1959–1980
22

New England Patriots
1964–1984
21

Kansas City Chiefs
1970–1990
1994–2014
21

Buffalo Bills^
1996–2016^
21

San Francisco 49ers
1950–1969
20

Chicago Bears
1964–1983
20

Seattle Seahawks
1985–2004
20

Cleveland Browns^
1995, 1999–2016^
19

Philadelphia Eagles
1961–1978
18

Denver Broncos
1960–1976
17

Tampa Bay Buccaneers
1980–1996
17

Green Bay Packers
1945–1960
16

Tennessee Titans
1962–1977
16

Los Angeles Chargers
1964–1979
16

Miami Dolphins^
2001–2016^
16

Oakland Raiders^
2003–2016^
14

New York Jets
1969–1981
13

Atlanta Falcons
1966–1977;
1979–1990
12

Dallas Cowboys
1997–2008
12

Houston Texans
2002–2010
9

Jacksonville Jaguars^
2008–2016^
9

Minnesota Vikings
1961–1968;
1989–1996
8

Carolina Panthers
2006–2013
8

Baltimore Ravens
2002–2007
6

Team
Longest streak with
no post-season victories
Seasons


document_title: Kilogram

question_text: what unit of mass is 1/1000 of a kilogram

root

text: Kilogram

text: Definition[edit]

text: The gram, 1/1000 of a kilogram, was provisionally defined in 1795 as the mass of one cubic centimetre of water at the melting point of ice.[4] The final kilogram, manufactured as a prototype in 1799 and from which the International Prototype Kilogram (IPK) was derived in 1875, had a mass equal to the mass of 1 dm3 of water under atmospheric pressure and at the temperature of its maximum density, which is approximately 4 °C.

tag: p

text: The kilogram is the only named SI unit with an SI prefix (kilo) as part of its name. It is also the only SI unit that is still directly defined by an artefact rather than a fundamental physical property that can be independently reproduced in different laboratories. Three other base units (cd, A, mol) and 17 derived units (N, Pa, J, W, C, V, F, Ω, S, Wb, T, H, kat, Gy, Sv, lm, lx) in the SI system are defined in relation to the kilogram, and thus its stability is important. The definitions of only eight other named SI units do not depend on the kilogram: those of temperature (K, °C), time and frequency (s, Hz, Bq), length (m), and angle (rad, sr).[5]

text: The IPK is rarely used or handled. Copies of the IPK kept by national metrology laboratories around the world were compared with the IPK in 1889, 1948, and 1989 to provide traceability of measurements of mass anywhere in the world back to the IPK.

text: The International Prototype Kilogram was commissioned by the General Conference on Weights and Measures (CGPM) under the authority of the Metre Convention (1875), and in the custody of the International Bureau of Weights and Measures (BIPM) who hold it on behalf of the CGPM. After the International Prototype Kilogram had been found to vary in mass over time relative to its reproductions, the International Committee for Weights and Measures (CIPM) recommended in 2005 that the kilogram be redefined in terms of a fundamental constant of nature. At its 2011 meeting, the CGPM agreed in principle that the kilogram should be redefined in terms of the Planck constant, h. The decision was originally deferred until 2014; in 2014 it was deferred again until the next meeting.[6] CIPM has proposed[7] revised definitions of the SI base units, for consideration at the 26th CGPM. The formal vote, scheduled for 16 November 2018,[8] is expected to be approved[9] and the new definitions will come into force on 20 May 2019.[10]

text: Name and terminology[edit]

text: The word kilogramme or kilogram is derived from the French kilogramme,[11] which itself was a learned coinage, prefixing the Greek stem of χίλιοι khilioi "a thousand" to gramma, a Late Latin term for "a small weight", itself from Greek γράμμα.[12] The word kilogramme was written into French law in 1795, in the Decree of 18 Germinal,[13] which revised the older system of units introduced by the French National Convention in 1793, where the gravet had been defined as weight (poids) of a cubic centimetre of water, equal to 1/1000 of a grave.[14] In the decree of 1795, the term gramme thus replaced gravet, and kilogramme replaced grave.

text: The French spelling was adopted in the United Kingdom when the word was used for the first time in English in 1797,[11] with the spelling kilogram being adopted in the United States. In the United Kingdom both spellings are used, with "kilogram" having become by far the more common.[15][Note 2] UK law regulating the units to be used when trading by weight or measure does not prevent the use of either spelling.[16]

text: In the 19th century the French word kilo, a shortening of kilogramme, was imported into the English language where it has been used to mean both kilogram[17] and kilometre.[18] While kilo is acceptable in many generalist texts, for example The Economist,[19] its use is typically considered inappropriate in certain applications including scientific, technical and legal writing, where authors should adhere strictly to SI nomenclature.[20][21] When the United States Congress gave the metric system legal status in 1866, it permitted the use of the word kilo as an alternative to the word kilogram,[22] but in 1990 revoked the status of the word kilo.[23]

text: During the 19th century, the standard system of metric units was the centimetre–gram–second system of units, treating the gram as the fundamental unit of mass and the kilogram simply as a derived unit. In 1901, however, following the discoveries by James Clerk Maxwell to the effect that electric measurements could not be explained in terms of the three fundamental units of length, mass and time, Giovanni Giorgi proposed a new standard system that would include a fourth fundamental unit to measure quantities in electromagnetism.[24] In 1935 this was adopted by the IEC as the Giorgi system, now also known as MKS system,[25] and in 1946 the CIPM approved a proposal to adopt the ampere as the electromagnetic unit of the "MKSA system".[26] :109,110 In 1948 the CGPM commissioned the CIPM "to make recommendations for a single practical system of units of measurement, suitable for adoption by all countries adhering to the Metre Convention".[27] This led to the launch of SI in 1960 and the subsequent publication of the "SI Brochure", which stated that "It is not permissible to use abbreviations for unit symbols or unit names ...".[28][Note 3] The CGS and MKS systems co-existed during much of the early-to-mid 20th century, but as a result of the decision to adopt the "Giorgi system" as the international system of units in 1960, the kilogram is now the SI base unit for mass, while the definition of the gram is derived from that of the kilogram.

text: Mass and weight[edit]

text: The kilogram is a unit of mass, a property corresponding to the common perception of how "heavy" an object is. Mass is an inertial property; that is, it is related to the tendency of an object at rest to remain at rest, or if in motion to remain in motion at a constant velocity, unless acted upon by a force.

text: While the weight of an object is dependent on the strength of the local gravitational field, the mass of an object is independent of gravity, as mass is a measure of the quantity of matter. Accordingly, for astronauts in microgravity, no effort is required to hold objects off the cabin floor; they are "weightless". However, since objects in microgravity still retain their mass and inertia, an astronaut must exert ten times as much force to accelerate a 10‑kilogram object at the same rate as a 1‑kilogram object.

text: Because at any given point on Earth the weight of an object is proportional to its mass, the mass of an object in kilograms is usually measured by comparing its weight to the weight of a standard mass, whose mass is known in kilograms, using a device called a weighing scale. The ratio of the force of gravity on the two objects, measured by the scale, is equal to the ratio of their masses.

text: Kilogramme des Archives[edit]

text: On April 7, 1795, the gram was decreed in France to be "the absolute weight of a volume of pure water equal to the cube of the hundredth part of the metre, and at the temperature of melting ice".[29]

text: Since trade and commerce typically involve items significantly more massive than one gram, and since a mass standard made of water would be inconvenient and unstable, the regulation of commerce necessitated the manufacture of a practical realization of the water-based definition of mass. Accordingly, a provisional mass standard was made as a single-piece, metallic artifact one thousand times as massive as the gram—the kilogram.

text: At the same time, work was commissioned to precisely determine the mass of a cubic decimetre (one litre) of water.[Note 4][29] Although the decreed definition of the kilogram specified water at 0 °C—its highly stable temperature point—the French chemist Louis Lefèvre-Gineau and the Italian naturalist Giovanni Fabbroni after several years of research chose to redefine the standard in 1799 to water's most stable density point: the temperature at which water reaches maximum density, which was measured at the time as 4 °C.[Note 5][30] They concluded that one cubic decimetre of water at its maximum density was equal to 99.9265% of the target mass of the provisional kilogram standard made four years earlier.[Note 6][31] That same year, 1799, an all-platinum kilogram prototype was fabricated with the objective that it would equal, as close as was scientifically feasible for the day, the mass of one cubic decimetre of water at 4 °C. The prototype was presented to the Archives of the Republic in June and on December 10, 1799, the prototype was formally ratified as the kilogramme des Archives (Kilogram of the Archives) and the kilogram was defined as being equal to its mass. This standard stood for the next 90 years.

text: International prototype kilogram[edit]

text: Since 1889 the magnitude of the kilogram has been defined as the mass of an object called the international prototype kilogram,[32] often referred to in the professional metrology world as the "IPK". The IPK is made of a platinum alloy known as "Pt‑10Ir", which is 90% platinum and 10% iridium (by mass) and is machined into a right-circular cylinder (height = diameter) of about 39 millimetres to minimize its surface area.[33] The addition of 10% iridium improved upon the all-platinum Kilogram of the Archives by greatly increasing hardness while still retaining platinum's many virtues: extreme resistance to oxidation, extremely high density (almost twice as dense as lead and more than 21 times as dense as water), satisfactory electrical and thermal conductivities, and low magnetic susceptibility. The IPK and its six sister copies are stored at the International Bureau of Weights and Measures (known by its French-language initials BIPM) in an environmentally monitored safe in the lower vault located in the basement of the BIPM's Pavillon de Breteuil in Saint-Cloud[Note 7] on the outskirts of Paris (see External images, below, for photographs). Three independently controlled keys are required to open the vault. Official copies of the IPK were made available to other nations to serve as their national standards. These are compared to the IPK roughly every 40 years, thereby providing traceability of local measurements back to the IPK.[34]

text: The Metre Convention was signed on May 20, 1875 and further formalized the metric system (a predecessor to the SI), quickly leading to the production of the IPK. The IPK is one of three cylinders made in 1879 by Johnson Matthey, which continues to manufacture nearly all of the national prototypes today.[35][36] In 1883, the mass of the IPK was found to be indistinguishable from that of the Kilogramme des Archives made eighty-four years prior, and was formally ratified as the kilogram by the 1st CGPM in 1889.[33]

text: Modern measurements of Vienna Standard Mean Ocean Water, which is pure distilled water with an isotopic composition representative of the average of the world's oceans, show that it has a density of 6999999975000000000♠0.999975 ±6994100000000000000♠0.000001 kg/L at its point of maximum density (3.984 °C) under one standard atmosphere (101 325 Pa or 760 torr) of pressure.[37] Thus, a cubic decimetre of water at its point of maximum density is only 25 parts per million less massive than the IPK; that is to say, the 25 milligram difference shows that the scientists over 219 years ago managed to make the mass of the Kilogram of the Archives equal that of a cubic decimetre of water at 4 °C, with a margin of error at most within the mass of a single excess grain of rice.

text: Copies of the international prototype kilogram[edit]

text: The various copies of the international prototype kilogram are given the following designations in the literature:

text:
The IPK itself. Located in Saint-Cloud, France.
Six sister copies, numbered: K1, 7, 8(41),[Note 8] 32, 43 and 47.[38] Located in Saint-Cloud, France.
Ten working copies, eight (9, 31, 42′, 63, 77, 88, 91, and 650[Note 9]) for routine use and two (25 and 73) for special use.[39] Located in Saint-Cloud, France.
National prototypes, stored in[40][41][42][43] Australia (44 and 87), Austria (49), Belgium (28 and 37), Brazil (66), Canada (50 and 74), China (60 and 64; 75 in Hong Kong), Czech Republic (67), Denmark (48), Egypt (58), Finland (23), France (35), Germany (52, 55 and 70), Hungary (16), India (57), Indonesia (46), Israel (71), Italy (5 and 76), Japan (6 and 94), Kazakhstan, Kenya (95), Mexico (21, 90 and 96), Netherlands (53), North Korea (68), Norway (36), Pakistan (93), Poland (51), Portugal (69), Romania (2), Russia (12 and 26[44]), Serbia (11 and 29), Singapore (83), Slovakia (41 and 65), South Africa (56), South Korea (39, 72 and 84), Spain (24 and 3), Sweden (40 and 86),[45] Switzerland (38 and 89), Taiwan (78), Thailand (80), Turkey (54[46]), United Kingdom (18,[47] 81 and 82) and the United States (20,[48] 4, 79, 85 and 92).
Some additional copies held by non-national organizations, such as the French Academy of Sciences in Paris (34) and the Istituto di Metrologia G. Colonnetti in Turin (62).[40]

tag: ul

text: Stability of the international prototype kilogram[edit]

text: By definition, the error in the measured value of the IPK's mass is exactly zero; the IPK is the kilogram. However, any changes in the IPK's mass over time can be deduced by comparing its mass to that of its official copies stored throughout the world, a rarely undertaken process called "periodic verification". The only three verifications occurred in 1889, 1948, and 1989. For instance, the US owns four 90% platinum / 10% iridium (Pt‑10Ir) kilogram standards, two of which, K4 and K20, are from the original batch of 40 replicas delivered in 1884.[Note 10] The K20 prototype was designated as the primary national standard of mass for the US. Both of these, as well as those from other nations, are periodically returned to the BIPM for verification. Extraordinary care is exercised when transporting prototypes. In 1984, the K4 and K20 prototypes were hand-carried in the passenger section of separate commercial airliners.

text: Note that none of the replicas has a mass precisely equal to that of the IPK; their masses are calibrated and documented as offset values. For instance, K20, the US's primary standard, originally had an official mass of 1 kg − 39 μg (micrograms) in 1889; that is to say, K20 was 39 μg less than the IPK. A verification performed in 1948 showed a mass of 1 kg − 19 μg. The latest verification performed in 1989 shows a mass precisely identical to its original 1889 value. Quite unlike transient variations such as this, the US's check standard, K4, has persistently declined in mass relative to the IPK—and for an identifiable reason: check standards are used much more often than primary standards and are prone to scratches and other wear. K4 was originally delivered with an official mass of 1 kg − 75 μg in 1889, but as of 1989 was officially calibrated at 1 kg − 106 μg and ten years later was 1 kg − 116 μg. Over a period of 110 years, K4 lost 41 μg relative to the IPK.[49]

text: Beyond the simple wear that check standards can experience, the mass of even the carefully stored national prototypes can drift relative to the IPK for a variety of reasons, some known and some unknown. Since the IPK and its replicas are stored in air (albeit under two or more nested bell jars), they gain mass through adsorption of atmospheric contamination onto their surfaces. Accordingly, they are cleaned in a process the BIPM developed between 1939 and 1946 known as "the BIPM cleaning method"[50] that comprises firmly rubbing with a chamois soaked in equal parts ether and ethanol, followed by steam cleaning with bi-distilled water, and allowing the prototypes to settle for 7–10 days before verification. Before the BIPM's published report in 1994 detailing the relative change in mass of the prototypes, different standard bodies used different techniques to clean their prototypes. The NIST's practice before then was to soak and rinse its two prototypes first in benzene, then in ethanol, and to then clean them with a jet of bi-distilled water steam. Cleaning the prototypes removes between 5 and 60 μg of contamination depending largely on the time elapsed since the last cleaning. Further, a second cleaning can remove up to 10 μg more. After cleaning—even when they are stored under their bell jars—the IPK and its replicas immediately begin gaining mass again. The BIPM even developed a model of this gain and concluded that it averaged 1.11 μg per month for the first 3 months after cleaning and then decreased to an average of about 1 μg per year thereafter. Since check standards like K4 are not cleaned for routine calibrations of other mass standards—a precaution to minimize the potential for wear and handling damage—the BIPM's model of time-dependent mass gain has been used as an "after cleaning" correction factor.

text: Because the first forty official copies are made of the same alloy as the IPK and are stored under similar conditions, periodic verifications using a large number of replicas—especially the national primary standards, which are rarely used—can convincingly demonstrate the stability of the IPK. What has become clear after the third periodic verification performed between 1988 and 1992 is that masses of the entire worldwide ensemble of prototypes have been slowly but inexorably diverging from each other. It is also clear that the mass of the IPK lost perhaps 50 μg over the last century, and possibly significantly more, in comparison to its official copies.[40][51] The reason for this drift has eluded physicists who have dedicated their careers to the SI unit of mass. No plausible mechanism has been proposed to explain either a steady decrease in the mass of the IPK, or an increase in that of its replicas dispersed throughout the world.[Note 11][52][53][54] Moreover, there are no technical means available to determine whether or not the entire worldwide ensemble of prototypes suffers from even greater long-term trends upwards or downwards because their mass "relative to an invariant of nature is unknown at a level below 1000 μg over a period of 100 or even 50 years".[51] Given the lack of data identifying which of the world's kilogram prototypes has been most stable in absolute terms, it is equally valid to state that the first batch of replicas has, as a group, gained an average of about 25 μg over one hundred years in comparison to the IPK.[Note 12]

text: What is known specifically about the IPK is that it exhibits a short-term instability of about 30 μg over a period of about a month in its after-cleaned mass.[55] The precise reason for this short-term instability is not understood but is thought to entail surface effects: microscopic differences between the prototypes' polished surfaces, possibly aggravated by hydrogen absorption due to catalysis of the volatile organic compounds that slowly deposit onto the prototypes as well as the hydrocarbon-based solvents used to clean them.[54][56]

text: It has been possible to rule out many explanations of the observed divergences in the masses of the world's prototypes proposed by scientists and the general public. The BIPM's FAQ explains, for example, that the divergence is dependent on the amount of time elapsed between measurements and not dependent on the number of times the prototype or its copies have been cleaned or possible changes in gravity or environment.[57] Reports published in 2013 by Peter Cumpson of Newcastle University based on the X-ray photoelectron spectroscopy of samples that were stored alongside various prototype kilograms suggested that one source of the divergence between the various prototypes could be traced to mercury that had been absorbed by the prototypes being in the proximity of mercury-based instruments. The IPK has been stored within centimetres of a mercury thermometer since at least as far back as the late 1980s.[58] In this Newcastle University work six platinum weights made in the nineteenth century were all found to have mercury at the surface, the most contaminated of which had the equivalent of 250 μg of mercury when scaled to the surface area of a kilogram prototype.

text: Scientists are seeing far greater variability in the prototypes than previously believed. The increasing divergence in the masses of the world's prototypes and the short-term instability in the IPK has prompted research into improved methods to obtain a smooth surface finish using diamond turning on newly manufactured replicas and has intensified the search for a new definition of the kilogram. See Proposed future definitions, below.[59]

text: Dependency of the SI on the IPK[edit]

text: The stability of the IPK is crucial because the kilogram underpins much of the SI system of measurement as it is currently defined and structured. For instance, the newton is defined as the force necessary to accelerate one kilogram at one metre per second squared. If the mass of the IPK were to change slightly, so too must the newton by a proportional degree. In turn, the pascal, the SI unit of pressure, is defined in terms of the newton. This chain of dependency follows to many other SI units of measure. For instance, the joule, the SI unit of energy, is defined as that expended when a force of one newton acts through one metre. Next to be affected is the SI unit of power, the watt, which is one joule per second. The ampere too is defined relative to the newton, and ultimately, the kilogram.

text: With the magnitude of the primary units of electricity thus determined by the kilogram, so too follow many others, namely the coulomb, volt, tesla, and weber. Even units used in the measure of light would be affected; the candela—following the change in the watt—would in turn affect the lumen and lux.

text: Because the magnitude of many of the units comprising the SI system of measurement is ultimately defined by the mass of a 139-year-old, golf-ball-sized piece of metal, the quality of the IPK must be diligently protected to preserve the integrity of the SI system. Yet, despite the best stewardship, the average mass of the worldwide ensemble of prototypes and the mass of the IPK have likely diverged another 6.8 μg since the third periodic verification 29 years ago.[Note 13] Further, the world's national metrology laboratories must wait for the fourth periodic verification to confirm whether the historical trends persisted.

text: Fortunately, definitions of the SI units are quite different from their practical realizations. For instance, the metre is defined as the distance light travels in a vacuum during a time interval of 1⁄299,792,458 of a second. However, the metre's practical realization typically takes the form of a helium–neon laser, and the metre's length is delineated—not defined—as 7006157980029872800♠1579800.298728 wavelengths of light from this laser. Now suppose that the official measurement of the second was found to have drifted by a few parts per billion (it is actually extremely stable with a reproducibility of a few parts in 1015).[60] There would be no automatic effect on the metre because the second—and thus the metre's length—is abstracted via the laser comprising the metre's practical realization. Scientists performing metre calibrations would simply continue to measure out the same number of laser wavelengths until an agreement was reached to do otherwise. The same is true with regard to the real-world dependency on the kilogram: if the mass of the IPK was found to have changed slightly, there would be no automatic effect upon the other units of measure because their practical realizations provide an insulating layer of abstraction. Any discrepancy would eventually have to be reconciled though, because the virtue of the SI system is its precise mathematical and logical harmony amongst its units. If the IPK's value were definitively proven to have changed, one solution would be to simply redefine the kilogram as being equal to the mass of the IPK plus an offset value, similarly to what is currently done with its replicas; e.g., "the kilogram is equal to the mass of the IPK + 42 parts per billion" (equivalent to 42 μg).

text: The long-term solution to this problem, however, is to liberate the SI system's dependency on the IPK by developing a practical realization of the kilogram that can be reproduced in different laboratories by following a written specification. The units of measure in such a practical realization would have their magnitudes precisely defined and expressed in terms of fundamental physical constants. While major portions of the SI system would still be based on the kilogram, the kilogram would in turn be based on invariant, universal constants of nature. Much work towards that end is ongoing, though no alternative has yet achieved the uncertainty of 20 parts per billion (~20 μg) required to improve upon the IPK.

text: Proposed future definitions[edit]

text: As of 2018 the International Prototype Kilogram was the only artefact referenced by the definition of the units of the SI, directly defining the kilogram and indirectly defining several other SI units. In 1960, the metre, previously similarly having been defined with reference to a single platinum-iridium bar with two marks on it, was redefined in terms of an invariant physical constant (the wavelength of a particular emission of light emitted by krypton,[61] and later the speed of light) so that the standard can be independently reproduced in different laboratories by following a written specification. At the 94th Meeting of the International Committee for Weights and Measures (CIPM) in 2005, it was recommended that the same be done with the kilogram.[62]

text: In October 2010, the CIPM voted to submit a resolution for consideration at the General Conference on Weights and Measures (CGPM), to "take note of an intention" that the kilogram be defined in terms of the Planck constant, h (which has dimensions of energy times time) together with other physical constants.[63][64] This resolution was accepted by the 24th conference of the CGPM[65] in October 2011 and further discussed at the 25th conference in 2014.[66][67] Although the Committee recognised that significant progress had been made, they concluded that the data did not appear sufficiently robust to adopt the revised definition, and that work should continue to enable the adoption at the 26th meeting, scheduled for 2018.[66] Such a definition would theoretically permit any apparatus that was capable of delineating the kilogram in terms of the Planck constant to be used as long as it possessed sufficient precision, accuracy and stability. The Kibble balance (discussed below) may be able to do this.

text: In the project to replace the last artefact that underpins much of the International System of Units (SI), a variety of other very different technologies and approaches were considered and explored over many years. They too are covered below. Some of these now-abandoned approaches were based on equipment and procedures that would have enabled the reproducible production of new, kilogram-mass prototypes on demand (albeit with extraordinary effort) using measurement techniques and material properties that are ultimately based on, or traceable to, physical constants. Others were based on devices that measured either the acceleration or weight of hand-tuned kilogram test masses and which expressed their magnitudes in electrical terms via special components that permit traceability to physical constants. All approaches depend on converting a weight measurement to a mass, and therefore require the precise measurement of the strength of gravity in laboratories. All approaches would have precisely fixed one or more constants of nature at a defined value.

text: Kibble balance[edit]

text: The Kibble balance (known as a "watt balance" before 2016) is essentially a single-pan weighing scale that measures the electric power necessary to oppose the weight of a kilogram test mass as it is pulled by Earth's gravity. It is a variation of an ampere balance in that it employs an extra calibration step that nulls the effect of geometry. The electric potential in the Kibble balance is delineated by a Josephson voltage standard, which allows voltage to be linked to an invariant constant of nature with extremely high precision and stability. Its circuit resistance is calibrated against a quantum Hall effect resistance standard.

text: The Kibble balance requires extremely precise measurement of the local gravitational acceleration g in the laboratory, using a gravimeter. For instance, the NIST compensates for Earth's gravity gradient of 309 μGal per metre when the elevation of the centre of the gravimeter differs from that of the nearby test mass in the Kibble balance; a change in the weight of a one-kilogram test mass that equates to about 316 μg/m.

text: In April 2007, the NIST's implementation of the Kibble balance demonstrated a combined relative standard uncertainty (CRSU) of 36 μg and a short-term resolution of 10−15 μg.[68][Note 14] The UK's National Physical Laboratory's Kibble balance demonstrated a CRSU of 70.3 μg in 2007.[69] That Kibble balance was disassembled and shipped in 2009 to Canada's Institute for National Measurement Standards (part of the National Research Council), where research and development with the device could continue.

text: If the CGPM adopts the new proposal and the new definition of the kilogram becomes part of the SI, the value in SI units of the Planck constant (h), which is a measure that relates the energy of particles such as photons to their frequency, would be precisely fixed (the currently accepted value of 6966662607004000000♠6.626070040(81)×10−34 J⋅s[70] has an uncertainty of about 1 in 23 million).[Note 15] Once agreed upon internationally, the kilogram would no longer be defined as the mass of the IPK. All the remaining unit definitions in the International System of Units (the SI) that today depend upon the kilogram and the joule would thus also have their magnitudes ultimately defined entirely in terms of constants of nature.

text: Gravity and the nature of the Kibble balance, which oscillates test masses up and down against the local gravitational acceleration g, are exploited so that mechanical power is compared against electrical power, which is the square of voltage divided by electrical resistance. However, g varies significantly—by nearly 1%—depending on where on the Earth's surface the measurement is made (see Earth's gravity). There are also slight seasonal variations in g at a location due to changes in underground water tables, and larger semimonthly and diurnal changes due to tidal distortions in the Earth's shape caused by the Moon and the Sun. Although g would not be a term in the definition of the kilogram, it would be crucial in the process of measurement of the kilogram when relating energy to power. Accordingly, g must be measured with at least as much precision and accuracy as are the other terms, so measurements of g must also be traceable to fundamental constants of nature. For the most precise work in mass metrology, g is measured using dropping-mass absolute gravimeters that contain an iodine-stabilized helium–neon laser interferometer. The fringe-signal, frequency-sweep output from the interferometer is measured with a rubidium atomic clock. Since this type of dropping-mass gravimeter derives its accuracy and stability from the constancy of the speed of light as well as the innate properties of helium, neon, and rubidium atoms, the 'gravity' term in the delineation of an all-electronic kilogram is also measured in terms of invariants of nature—and with very high precision. For instance, in the basement of the NIST's Gaithersburg facility in 2009, when measuring the gravity acting upon Pt‑10Ir test masses (which are denser, smaller, and have a slightly lower center of gravity inside the Kibble balance than stainless steel masses), the measured value was typically within 8 ppb of 7000980101644000000♠9.80101644 m/s2.[71]

text: The virtue of electronic realizations like the Kibble balance is that the definition and dissemination of the kilogram would no longer be dependent upon the stability of kilogram prototypes, which must be very carefully handled and stored. It would free physicists from the need to rely on assumptions about the stability of those prototypes. Instead, hand-tuned, close-approximation mass standards would simply be weighed and documented as being equal to one kilogram plus an offset value. With the Kibble balance, while the kilogram would be delineated in electrical and gravity terms, all of which are traceable to invariants of nature; it would be defined in a manner that is directly traceable to three fundamental constants of nature. The Planck constant defines the kilogram in terms of the second and the metre. By fixing the Planck constant, the definition of the kilogram would in addition depend only on the definitions of the second and the metre. The definition of the second depends on a single defined physical constant: the ground state hyperfine splitting frequency of the caesium 133 atom Δν(133Cs)hfs. The metre depends on the second and on an additional defined physical constant: the speed of light c. If the kilogram is redefined in this manner, physical objects such as the IPK would no longer be part of the definition, but would instead become transfer standards.

text: Scales like the Kibble balance also permit more flexibility in choosing materials with especially desirable properties for mass standards. For instance, Pt‑10Ir could continue to be used so that the specific gravity of newly produced mass standards would be the same as existing national primary and check standards (≈21.55 g/ml). This would reduce the relative uncertainty when making mass comparisons in air. Alternatively, entirely different materials and constructions could be explored with the objective of producing mass standards with greater stability. For instance, osmium-iridium alloys could be investigated if platinum's propensity to absorb hydrogen (due to catalysis of VOCs and hydrocarbon-based cleaning solvents) and atmospheric mercury proved to be sources of instability. Also, vapor-deposited, protective ceramic coatings like nitrides could be investigated for their suitability for chemically isolating these new alloys.

text: The challenge with Kibble balances is not only in reducing their uncertainty, but also in making them truly practical realizations of the kilogram. Nearly every aspect of Kibble balances and their support equipment requires such extraordinarily precise and accurate, state-of-the-art technology that—unlike a device like an atomic clock—few countries would currently choose to fund their operation. For instance, the NIST's Kibble balance used four resistance standards in 2007, each of which was rotated through the Kibble balance every two to six weeks after being calibrated in a different part of NIST headquarters facility in Gaithersburg, Maryland. It was found that simply moving the resistance standards down the hall to the Kibble balance after calibration altered their values 10 ppb (equivalent to 10 μg) or more.[72] Present-day technology is insufficient to permit stable operation of Kibble balances between even biannual calibrations. If the kilogram is defined in terms of the Planck constant, it is likely there will only be a few—at most—Kibble balances initially operating in the world.

text: Alternative approaches to redefining the kilogram that were fundamentally different from the Kibble balance were explored to varying degrees with some abandoned, as follows:

text: Atom-counting approaches[edit]

text: Though not offering a practical realization, this definition would precisely define the magnitude of the kilogram in terms of a certain number of carbon‑12 atoms. Carbon‑12 (12C) is an isotope of carbon. The mole is currently defined as "the quantity of entities (elementary particles like atoms or molecules) equal to the number of atoms in 12 grams of carbon‑12". Thus, the current definition of the mole requires that 1000⁄12 moles (83 1⁄3 mol) of 12C has a mass of precisely one kilogram. The number of atoms in a mole, a quantity known as the Avogadro constant, is experimentally determined, and the current best estimate of its value is 7023602214085700000♠6.022140857(74)×1023 entities per mole.[73] This new definition of the kilogram proposed to fix the Avogadro constant at precisely 6.02214X×10^23 with the kilogram being defined as "the mass equal to that of 1000⁄12 ⋅ 6.02214X×10^23 atoms of 12C".

text: The accuracy of the measured value of the Avogadro constant is currently limited by the uncertainty in the value of the Planck constant. That relative standard uncertainty has been 50 parts per billion (ppb) since 2006. By fixing the Avogadro constant, the practical effect of this proposal would be that the uncertainty in the mass of a 12C atom—and the magnitude of the kilogram—could be no better than the current 50 ppb uncertainty in the Planck constant. Under this proposal, the magnitude of the kilogram would be subject to future refinement as improved measurements of the value of the Planck constant become available; electronic realizations of the kilogram would be recalibrated as required. Conversely, an electronic definition of the kilogram (see § Electronic approaches, below), which would precisely fix the Planck constant, would continue to allow 83 1⁄3 moles of 12C to have a mass of precisely one kilogram but the number of atoms comprising a mole (the Avogadro constant) would continue to be subject to future refinement.

text: A variation on a 12C-based definition proposes to define the Avogadro constant as being precisely 7007844468890000000♠844468893 (≈ 7023602214162000000♠6.02214162×1023) atoms. An imaginary realization of a 12-gram mass prototype would be a cube of 12C atoms measuring precisely 7007844468890000000♠84446889 atoms across on a side. With this proposal, the kilogram would be defined as "the mass equal to 7010844468890000000♠84446889×103 × 83 1⁄3 atoms of 12C."[74][Note 16]

text: Avogadro project[edit]

text: Another Avogadro constant-based approach, known as the International Avogadro Coordination's Avogadro project, would define and delineate the kilogram as a 93.6 mm diameter sphere of silicon atoms. Silicon was chosen because a commercial infrastructure with mature processes for creating defect-free, ultra-pure monocrystalline silicon already exists to service the semiconductor industry. To make a practical realization of the kilogram, a silicon boule (a rod-like, single-crystal ingot) would be produced. Its isotopic composition would be measured with a mass spectrometer to determine its average relative atomic mass. The boule would be cut, ground, and polished into spheres. The size of a select sphere would be measured using optical interferometry to an uncertainty of about 0.3 nm on the radius—roughly a single atomic layer. The precise lattice spacing between the atoms in its crystal structure (≈ 192 pm) would be measured using a scanning X-ray interferometer. This permits its atomic spacing to be determined with an uncertainty of only three parts per billion. With the size of the sphere, its average atomic mass, and its atomic spacing known, the required sphere diameter can be calculated with sufficient precision and low uncertainty to enable it to be finish-polished to a target mass of one kilogram.

text: Experiments are being performed on the Avogadro Project's silicon spheres to determine whether their masses are most stable when stored in a vacuum, a partial vacuum, or ambient pressure. However, no technical means currently exist to prove a long-term stability any better than that of the IPK's, because the most sensitive and accurate measurements of mass are made with dual-pan balances like the BIPM's FB‑2 flexure-strip balance (see § External links, below). Balances can only compare the mass of a silicon sphere to that of a reference mass. Given the latest understanding of the lack of long-term mass stability with the IPK and its replicas, there is no known, perfectly stable mass artefact to compare against. Single-pan scales, which measure weight relative to an invariant of nature, are not precise to the necessary long-term uncertainty of 10–20 parts per billion. Another issue to be overcome is that silicon oxidizes and forms a thin layer (equivalent to 5–20 silicon atoms deep) of silicon dioxide (quartz) and silicon monoxide. This layer slightly increases the mass of the sphere, an effect that must be accounted for when polishing the sphere to its finished size. Oxidation is not an issue with platinum and iridium, both of which are noble metals that are roughly as cathodic as oxygen and therefore don't oxidize unless coaxed to do so in the laboratory. The presence of the thin oxide layer on a silicon-sphere mass prototype places additional restrictions on the procedures that might be suitable to clean it to avoid changing the layer's thickness or oxide stoichiometry.

text: All silicon-based approaches would fix the Avogadro constant but vary in the details of the definition of the kilogram. One approach would use silicon with all three of its natural isotopes present. About 7.78% of silicon comprises the two heavier isotopes: 29Si and 30Si. As described in § Carbon-12 above, this method would define the magnitude of the kilogram in terms of a certain number of 12C atoms by fixing the Avogadro constant; the silicon sphere would be the practical realization. This approach could accurately delineate the magnitude of the kilogram because the masses of the three silicon nuclides relative to 12C are known with great precision (relative uncertainties of 1 ppb or better). An alternative method for creating a silicon sphere-based kilogram proposes to use isotopic separation techniques to enrich the silicon until it is nearly pure 28Si, which has a relative atomic mass of 7001279769265325000♠27.9769265325(19).[76] With this approach, the Avogadro constant would not only be fixed, but so too would the atomic mass of 28Si. As such, the definition of the kilogram would be decoupled from 12C and the kilogram would instead be defined as 1000⁄7001279769265325000♠27.9769265325 ⋅ 7023602214179000000♠6.02214179×1023 atoms of 28Si (≈ 7001357437404300000♠35.74374043 fixed moles of 28Si atoms). Physicists could elect to define the kilogram in terms of 28Si even when kilogram prototypes are made of natural silicon (all three isotopes present). Even with a kilogram definition based on theoretically pure 28Si, a silicon-sphere prototype made of only nearly pure 28Si would necessarily deviate slightly from the defined number of moles of silicon to compensate for various chemical and isotopic impurities as well as the effect of surface oxides.[77]

text: Ion accumulation[edit]

text: Another Avogadro-based approach, ion accumulation, since abandoned, would have defined and delineated the kilogram by precisely creating new metal prototypes on demand. It would have done so by accumulating gold or bismuth ions (atoms stripped of an electron) and counting them by measuring the electric current required to neutralize the ions. Gold (197Au) and bismuth (209Bi) were chosen because they can be safely handled and have the two highest atomic masses among the mononuclidic elements that is effectively non-radioactive (bismuth) or is perfectly stable (gold). See also Table of nuclides.[Note 18]

text: With a gold-based definition of the kilogram for instance, the relative atomic mass of gold could have been fixed as precisely 7002196966568700000♠196.9665687, from the current value of 7002196966568700000♠196.9665687(6). As with a definition based upon carbon‑12, the Avogadro constant would also have been fixed. The kilogram would then have been defined as "the mass equal to that of precisely 1000⁄7002196966568700000♠196.9665687 ⋅ 7023602214179000000♠6.02214179×1023 atoms of gold" (precisely 3,057,443,620,887,933,963,384,315 atoms of gold or about 7000507700370999999♠5.07700371 fixed moles).

text: In 2003, German experiments with gold at a current of only 10 μA demonstrated a relative uncertainty of 1.5%.[78] Follow-on experiments using bismuth ions and a current of 30 mA were expected to accumulate a mass of 30 g in six days and to have a relative uncertainty of better than 1 ppm.[79] Ultimately, ion‑accumulation approaches proved to be unsuitable. Measurements required months and the data proved too erratic for the technique to be considered a viable future replacement to the IPK.[80]

text: Among the many technical challenges of the ion-deposition apparatus was obtaining a sufficiently high ion current (mass deposition rate) while simultaneously decelerating the ions so they could all deposit onto a target electrode embedded in a balance pan. Experiments with gold showed the ions had to be decelerated to very low energies to avoid sputtering effects—a phenomenon whereby ions that had already been counted ricochet off the target electrode or even dislodged atoms that had already been deposited. The deposited mass fraction in the 2003 German experiments only approached very close to 100% at ion energies of less than around 1 eV (< 1 km/s for gold).[78]

text: If the kilogram had been defined as a precise quantity of gold or bismuth atoms deposited with an electric current, not only would the Avogadro constant and the atomic mass of gold or bismuth have to have been precisely fixed, but also the value of the elementary charge (e), likely to 1.60217X×10^−19 C (from the currently recommended value of 6981160217662079999♠1.6021766208(98)×10−19 C[81]). Doing so would have effectively defined the ampere as a flow of 1⁄1.60217X×10^−19 electrons per second past a fixed point in an electric circuit. The SI unit of mass would have been fully defined by having precisely fixed the values of the Avogadro constant and elementary charge, and by exploiting the fact that the atomic masses of bismuth and gold atoms are invariant, universal constants of nature.

text: Beyond the slowness of making a new mass standard and the poor reproducibility, there were other intrinsic shortcomings to the ion‑accumulation approach that proved to be formidable obstacles to ion-accumulation-based techniques becoming a practical realization. The apparatus necessarily required that the deposition chamber have an integral balance system to enable the convenient calibration of a reasonable quantity of transfer standards relative to any single internal ion-deposited prototype. Furthermore, the mass prototypes produced by ion deposition techniques would have been nothing like the freestanding platinum-iridium prototypes currently in use; they would have been deposited onto—and become part of—an electrode imbedded into one pan of a special balance integrated into the device. Moreover, the ion-deposited mass wouldn't have had a hard, highly polished surface that can be vigorously cleaned like those of current prototypes. Gold, while dense and a noble metal (resistant to oxidation and the formation of other compounds), is extremely soft so an internal gold prototype would have to be kept well isolated and scrupulously clean to avoid contamination and the potential of wear from having to remove the contamination. Bismuth, which is an inexpensive metal used in low-temperature solders, slowly oxidizes when exposed to room-temperature air and forms other chemical compounds and so would not have produced stable reference masses unless it was continually maintained in a vacuum or inert atmosphere.

text: Ampere-based force[edit]

text: This approach would define the kilogram as "the mass which would be accelerated at precisely 6993200000000000000♠2×10−7 m/s2 when subjected to the per-metre force between two straight parallel conductors of infinite length, of negligible circular cross section, placed one metre apart in vacuum, through which flow a constant current of 1⁄1.60217X×10^−19 elementary charges per second".

text: Effectively, this would define the kilogram as a derivative of the ampere rather than the present relationship, which defines the ampere as a derivative of the kilogram. This redefinition of the kilogram would specify elementary charge (e) as precisely 1.60217X×10^−19 coulomb rather than the current recommended value of 6981160217662079999♠1.6021766208(98)×10−19 C.[81] It would necessarily follow that the ampere (one coulomb per second) would also become an electric current of this precise quantity of elementary charges per second passing a given point in an electric circuit. The virtue of a practical realization based upon this definition is that unlike the Kibble balance and other scale-based methods, all of which require the careful characterization of gravity in the laboratory, this method delineates the magnitude of the kilogram directly in the very terms that define the nature of mass: acceleration due to an applied force. Unfortunately, it is extremely difficult to develop a practical realization based upon accelerating masses. Experiments over a period of years in Japan with a superconducting, 30 g mass supported by diamagnetic levitation never achieved an uncertainty better than ten parts per million. Magnetic hysteresis was one of the limiting issues. Other groups performed similar research that used different techniques to levitate the mass.[82][83]

text: SI multiples[edit]

text: Because SI prefixes may not be concatenated (serially linked) within the name or symbol for a unit of measure, SI prefixes are used with the gram, not the kilogram, which already has a prefix as part of its name.[84] For instance, one-millionth of a kilogram is 1 mg (one milligram), not 1 μkg (one microkilogram).

text:
SI multiples for gram (g)

Submultiples

Multiples

Value
SI symbol
Name
Value
SI symbol
Name

10−1 g
dg
decigram
101 g
dag
decagram

10−2 g
cg
centigram
102 g
hg
hectogram

10−3 g
mg
milligram
103 g
kg
kilogram

10−6 g
µg
microgram
106 g
Mg
megagram (tonne)

10−9 g
ng
nanogram
109 g
Gg
gigagram

10−12 g
pg
picogram
1012 g
Tg
teragram

10−15 g
fg
femtogram
1015 g
Pg
petagram

10−18 g
ag
attogram
1018 g
Eg
exagram

10−21 g
zg
zeptogram
1021 g
Zg
zettagram

10−24 g
yg
yoctogram
1024 g
Yg
yottagram

Common prefixed units are in bold face.[Note 19]

tag: table

text:
The microgram is typically abbreviated "mcg" in pharmaceutical and nutritional supplement labelling, to avoid confusion, since the "μ" prefix is not always well recognized outside of technical disciplines.[Note 20] (The expression "mcg" is also the symbol for an obsolete CGS unit of measure known as the "millicentigram", which is equal to 10 μg.)
In the United Kingdom, because serious medication errors have been made from the confusion between milligrams and micrograms when micrograms has been abbreviated, the recommendation given in the Scottish Palliative Care Guidelines is that doses of less than one milligram must be expressed in micrograms and that the word microgram must be written in full, and that it is never acceptable to use "mcg" or "μg".[2]
The hectogram is a very commonly used unit in the retail food trade in Italy, usually called an etto, short for ettogrammo, the Italian for hectogram.[85][86][87]
The former standard spelling and abbreviation "deka-" and "dk" produced abbreviations such as "dkm" (dekametre) and "dkg" (dekagram).[88] The abbreviation "dkg" is still used in parts of central Europe in retail for some foods such as cheese and meat.[citation needed]
The unit name megagram is rarely used, and even then typically only in technical fields in contexts where especially rigorous consistency with the SI standard is desired. For most purposes, the name tonne is instead used. The tonne and its symbol, "t", were adopted by the CIPM in 1879. It is a non-SI unit accepted by the BIPM for use with the SI. According to the BIPM, "In English speaking countries this unit is usually called 'metric ton'."[89] The unit name megatonne or megaton (Mt) is often used in general-interest literature on greenhouse gas emissions, whereas the equivalent unit in scientific papers on the subject is often the teragram (Tg).