UK and US bra bands share the same number — a UK 36 is a US 36. Cups match through D and DD, then a UK E is a US DDD, a UK F is a US G, and a UK FF is a US H.
Band size needs no conversion at all between UK and US — both use the same inch-based numbering, so a UK 28 is a US 28 and a UK 42 is a US 42 without any adjustment.
Cup letters match through D and, unusually, through DD as well — both systems use that exact label for the size right after D. Beyond DD they split: a UK E is a US DDD, a UK F is a US G, a UK FF is a US H, and a UK G is a US I. This converter looks up the actual row rather than assuming the alphabets stay aligned once you're two letters past D.
| Band (UK) | Band (US) |
|---|---|
| 28 | 28 |
| 30 | 30 |
| 32 | 32 |
| 34 | 34 |
| 36 | 36 |
| 38 | 38 |
| 40 | 40 |
| 42 | 42 |
| 44 | 44 |
| Cup (UK) | Cup (US) |
|---|---|
| AA | AA |
| A | A |
| B | B |
| C | C |
| D | D |
| DD | DD / E |
| E | DDD / F |
| F | G / DDDD |
| FF | H |
| G | I |
| GG | J |
| H | K |
Cup letters match through D; above D the systems diverge, which is why the cup half of this chart is a lookup, never a formula.
Yes — UK and US bra bands are the same inch scale, so the number is identical in both systems.
UK E converts to US DDD (also printed as F by some US brands).
They match through DD. The size after that — UK E — is where the two systems begin using different letters for the same physical cup.