Bra Cup Sizes in Order
Cup size is the difference between your bust and your band measurement — each inch of difference is one cup up. Here's the full order, and where the US and UK letters stop matching.
AA · A · B · C · D · DD · then US: DDD/F · G · H · I … / UK: E · F · FF · G …
Everyone agrees up to a D. Above D the two systems split: the US stacks letters (DD, DDD) before jumping to F, G, H; the UK inserts single and doubled letters (DD, E, F, FF, G, GG). That's why a US DDD is roughly a UK E and an EU F. One inch of bust-minus-band = one cup, whatever the label.
Cup size chart (US · UK · EU)
| Bust − band | US | UK | EU |
|---|---|---|---|
| 0" | 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/F | E | F |
| 7" | G | F | G |
| 8" | H | FF | H |
| 9" | I | G | I |
FAQ
What is the order of bra cup sizes?
From smallest: AA, A, B, C, D, then the systems diverge. US continues DD, DDD (F), G, H, I…; the UK uses DD, E, F, FF, G, GG… Each step up is about one more inch of bust-minus-band difference.
Is a D cup bigger than a DD?
No — DD (also written E in the UK) is one cup larger than D. The order is …C, D, DD/E, then F and up.
Why do US and UK cups differ above D?
Both agree up to D. Above that, the US doubles letters (DD, DDD) before moving to F/G, while the UK inserts single letters (E, F, FF, G). So a US DDD ≈ a UK E ≈ EU F.
Does the same letter mean the same size on every band?
No. Cup size is relative to the band — a 32C is a smaller cup than a 38C — because it's measured as bust minus band. See our guide on sister sizes.
Based on the standard difference method and common US/UK/EU cup lettering. General reference; brands vary.