A woman compares two sister sizes to her correctly-fitting bra (right).[1]

A sister size is a related bra size with the same cup volume of each other. One could, in theory, be used as a substitute for one's true size, but the bra wouldn't fit correctly.[2]


Despite different band sizes, sister sizes always have the same cup volume as each other.[3]

Sister sizes have the same cup volume as each other. The difference of band size simply changes the fit.

Typical stores suggest sister sizes to sell their limited inventory to the customer, as opposed to a bra that actually fits. This perpetuates the problem of most women wearing band sizes too large, with correspondingly wrong cup sizes.[2]

Sometimes, two adjacent sister sizes may both fit a woman, since the cup volume is the same, while the band size can be adjusted to a small degree by using the hook and eye fasteners in the bra clasp.[2] Usually, it much less comfortable and flattering, however.


Main article: Bra sizing by country

UK sister sizes

Sister sizes (UK sizing)
26 28 30 32 34 36 38 40 42 44 46 48 50 52 54
26A 28AA
26B 28A 30AA
26C 28B 30A 32AA
26D 28C 30B 32A 34AA
26DD 28D 30C 32B 34A 36AA
26E 28DD 30D 32C 34B 36C 38AA
26F 28E 30DD 32D 34C 36B 38A 40AA
26FF 28F 30E 32DD 34D 36C 38B 40A 42AA
26G 28FF 30F 32E 34DD 36D 38C 40B 42A 44AA
26GG 28G 30FF 32F 34E 36DD 38D 40C 42B 44A 46AA
26H 28GG 30G 32FF 34F 36E 38DD 40D 42C 44B 46A 48AA
26HH 28H 30GG 32G 34FF 36F 38E 40DD 42D 44C 46B 48A 50AA
26J 28HH 30H 32GG 34G 36FF 38F 38E 42DD 44D 46C 48B 50A 52AA
26JJ 28J 30HH 32H 34GG 36G 38FF 40F 40E 44DD 46D 48C 50B 52A 54AA
26K 28JJ 30J 32HH 34H 36GG 38G 40FF 42F 44E 46DD 48D 50C 52B 54A
26KK 28K 30JJ 32J 34HH 36H 38GG 40G 42FF 44F 46E 48DD 50D 52C 54B
26L 28KK 30K 32JJ 34J 36HH 38H 40GG 42G 44FF 46F 48E 50DD 52D 54C
26LL 28L 30KK 32K 34JJ 36J 38HH 40H 42GG 44G 46FF 48F 50E 52DD 54D
26M 28LL 30L 32KK 34K 36JJ 38J 40HH 42H 44GG 46G 48FF 50F 52E 54DD
26MM 28M 30LL 32L 34KK 36K 38JJ 40J 42HH 44H 46GG 48G 50FF 52F 54E
26N 28MM 30M 32LL 34L 36KK 38K 40JJ 42J 44HH 46H 48GG 50G 52FF 54F
28N 30MM 32M 34LL 36L 38KK 40K 42JJ 44J 46HH 48H 50GG 52G 54FF
30N 32MM 34M 36LL 38L 40KK 42K 44JJ 46J 48HH 50H 52GG 54G
32N 34MM 36M 38LL 40L 42KK 44K 46JJ 48J 50HH 52H 54GG
34N 36MM 38M 40LL 42L 44KK 46K 48JJ 50J 52HH 54H
36N 38MM 40M 42LL 44L 46KK 48K 50JJ 52J 54HH
38N 40MM 42M 44LL 46L 48KK 50K 52JJ 54J
40N 42MM 44M 46LL 48L 50KK 52K 54JJ
42N 44MM 46M 48LL 50L 52KK 54K
44N 46MM 48M 50LL 52L 54KK
46N 48MM 50M 52LL 54L
48N 50MM 52M 54LL
50N 52MM 54M
52N 54MM

US sister sizes

Sister sizes (US sizing)
28 30 32 34 36 38 40 42 44 46 48 50 52 54 56
28A 30AA
28B 30A 32AA
28C 30B 32A 34AA
28D 30C 32B 34A 36AA
28DD/E 30D 32C 34B 36A 37AA
28DDD/E/F 30DD/E 32D 34C 36B 38A 40AA
28DDDD/F/G 30DDD/E/F 32DD/E 34D 36C 38B 40A 42AA
28G/H/J 30DDDD/F/G 32DDD/E/F 34DD/E 36D 38C 40B 42A 44AA
28I/J/K 30G/H/J 32DDDD/F/G 34DDD/E/F 36DD/E 38D 40C 42B 44A 46AA
28J 30I/J/K 32G/H/J 34DDDD/F/G 36DDD/E/F 38DD/E 40D 42C 44B 46A 48AA
28K 30J 32I/J/K 34G/H/J 36DDDD/F/G 38DDD/E/F 40DD/E 42D 44C 46B 48A 50AA
28L 30K 32J 34I/J/K 36G/H/J 38DDDD/F/G 40DDD/E/F 42DD/E 44D 46C 48B 50A 52AA
28M 30L 32K 34J 36I/J/K 38G/H/J 40DDDD/F/G 42DDD/E/F 44DD/E 46D 48C 50B 52A 54AA
28N 30M 32L 34K 36J 38I/J/K 40G/H/J 42DDDD/F/G 44DDD/E/F 46DD/E 48D 50C 52B 54A 56AA
30N 32M 34L 36K 38J 40I/J/K 42G/H/J 44DDDD/F/G 46DDD/E/F 48DD/E 50D 52C 54B 56A
32N 34M 36L 38K 40J 42I/J/K 44G/H/J 46DDD/F/G 48DDD/E/F 50DD/E 52D 54C 56B
34N 36M 38L 40K 42J 44I/J/K 46G/H/J 48DDD/F/G 50DDD/E/F 52DD/E 54D 56C
36N 38M 40L 42K 44J 46I/J/K 48G/H/J 50DDD/F/G 52DDD/E/F 54DD/E 56D
38N 40M 42L 44K 46J 48I/J/K 50G/H/J 52DDD/F/G 54DDD/E/F 56DD/E
40N 42M 44L 46K 48J 50I/J/K 52G/H/J 54DDD/F/G 56DDD/E/F
42N 44M 46L 48K 50J 52I/J/K 54G/H/J 56DDD/F/G
44N 46M 48L 50K 52J 54I/J/K 56G/H/J
46N 48M 50L 52K 54J 56I/J/K
48N 50M 52L 54K 56J
50N 52M 54L 56K
52N 54M 56L
54N 56M




See also


Community content is available under CC-BY-SA unless otherwise noted.