Bra Cup Sizes in Order, Smallest to Largest

Q: What are the bra cup sizes in order?

From smallest: AA, A, B, C, D, then the systems diverge. US continues DD, DDD, G, H onward; UK runs DD, E, F, FF, G, GG, H, HH, J, JJ, K; EU uses single letters E through P. Each letter is about one inch more bust-band difference.

Q: What cup size comes after DDD?

In US sizing, G (some brands use F). The UK equivalent of DDD is E, followed by F, FF and G. This divergence is why a UK G and a US G are different volumes.

Q: What is the smallest cup size?

AA, representing less than an inch of bust-band difference, with AAA appearing in a few specialty ranges below it. Small cups are proportionate, not deficient, and fit best in demi and shallow-profile styles.

Q: What is the biggest cup size?

Mainstream extended ranges reach about K (UK) or P (EU lettering); beyond that, Polish semi-custom makers grade further. Letters past the chart mostly signal that specialist brands, not bigger mall sizes, are the answer.

7 sizing systems25+ country calculatorsBands 28-60, cups AA-PZero data stored

Cup letters run in a simple order that splits into dialects after D. Below is the full ladder, smallest to largest, in all three lettering systems side by side, each row representing roughly one more inch of bust-band difference.

Difference (in)	US	UK	EU
<1	AA	AA	AA
1	A	A	A
2	B	B	B
3	C	C	C
4	D	D	D
5	DD	DD	E
6	DDD	E	F
7	G	F	G
8	H	FF	H
9	I	G	I
10	J	GG	J
11	K	H	K
12	L	HH	L
13	M	J	M
14	N	JJ	N
15	O	K	O
16	P	KK	P

Reading the ladder correctly

Two things make cup orders confusing. First, the US double-letter habit: DD and DDD are real steps, not emphasis, sitting between D and G. Second, the divergence: a UK F is a US DDD-and-a-bit, an EU F is different again, so a letter without its system attached is ambiguous past D. When comparing across systems, convert through the inch difference (the left column) or use the converter, which does it precisely.

And the eternal reminder: a letter alone is not a size. Every letter in this table exists on bands 28 through 60, and a 30G holds less than a 38D. The comparison tool settles any two specific sizes.

Frequently asked questions

What are the bra cup sizes in order?

From smallest: AA, A, B, C, D, then the systems diverge. US continues DD, DDD, G, H onward; UK runs DD, E, F, FF, G, GG, H, HH, J, JJ, K; EU uses single letters E through P. Each letter is about one inch more bust-band difference.

What cup size comes after DDD?

In US sizing, G (some brands use F). The UK equivalent of DDD is E, followed by F, FF and G. This divergence is why a UK G and a US G are different volumes.

What is the smallest cup size?

AA, representing less than an inch of bust-band difference, with AAA appearing in a few specialty ranges below it. Small cups are proportionate, not deficient, and fit best in demi and shallow-profile styles.

What is the biggest cup size?

Mainstream extended ranges reach about K (UK) or P (EU lettering); beyond that, Polish semi-custom makers grade further. Letters past the chart mostly signal that specialist brands, not bigger mall sizes, are the answer.

Written by the BraSizeConversion fit team. Last updated August 2026.

Difference (in)	US	UK	EU
<1	AA	AA	AA
1	A	A	A
2	B	B	B
3	C	C	C
4	D	D	D
5	DD	DD	E
6	DDD	E	F
7	G	F	G
8	H	FF	H
9	I	G	I
10	J	GG	J
11	K	H	K
12	L	HH	L
13	M	J	M
14	N	JJ	N
15	O	K	O
16	P	KK	P

Difference (in)	US	UK	EU
<1	AA	AA	AA
1	A	A	A
2	B	B	B
3	C	C	C
4	D	D	D
5	DD	DD	E
6	DDD	E	F
7	G	F	G
8	H	FF	H
9	I	G	I
10	J	GG	J
11	K	H	K
12	L	HH	L
13	M	J	M
14	N	JJ	N
15	O	K	O
16	P	KK	P

Difference (in)	US	UK	EU
<1	AA	AA	AA
1	A	A	A
2	B	B	B
3	C	C	C
4	D	D	D
5	DD	DD	E
6	DDD	E	F
7	G	F	G
8	H	FF	H
9	I	G	I
10	J	GG	J
11	K	H	K
12	L	HH	L
13	M	J	M
14	N	JJ	N
15	O	K	O
16	P	KK	P