Reference · Updated June 2026
Bra size reference
Band and cup conversion across five sizing systems. Use the under-bust measurement column to find your band; use the cup difference (bust minus under-bust) to find your cup.
| US | UK | EU | FR | AU | Under-bust (cm) |
|---|---|---|---|---|---|
| 30 | 30 | 65 | 80 | 8 | 63-67 |
| 32 | 32 | 70 | 85 | 10 | 68-72 |
| 34 | 34 | 75 | 90 | 12 | 73-77 |
| 36 | 36 | 80 | 95 | 14 | 78-82 |
| 38 | 38 | 85 | 100 | 16 | 83-87 |
| 40 | 40 | 90 | 105 | 18 | 88-92 |
| 42 | 42 | 95 | 110 | 20 | 93-97 |
| 44 | 44 | 100 | 115 | 22 | 98-102 |
| US | UK | EU | Bust − under-bust |
|---|---|---|---|
| AA | AA | AA | 10-12 cm |
| A | A | A | 12-14 cm |
| B | B | B | 14-16 cm |
| C | C | C | 16-18 cm |
| D | D | D | 18-20 cm |
| DD | DD | E | 20-22 cm |
| DDD/F | E | F | 22-24 cm |
| G | F | G | 24-26 cm |
| H | FF | H | 26-28 cm |
| I | G | I | 28-30 cm |
Measure under-bust first
Wrap a soft tape directly under the bust, snug but not tight. That measurement gives you the band size — round to the nearest even number for US/UK, or use the EU column directly.
Then measure across the bust
Measure around the fullest part of the bust while wearing an unpadded bra. Subtract the under-bust from this number; the difference determines the cup.
UK and EU diverge above DD
Above DD the UK system uses E, F, FF, G while the EU continues E, F, G, H. A UK F is closer to a EU G — always cross-check on the cup table when buying from European brands.
Sister sizing
If a band is too tight, go up one band and down one cup (e.g. 34C → 36B) to maintain a similar cup volume.
Common questions
- Why does my US 34B feel different in a UK brand?
- UK 34B = US 34B in label, but cup grading is more consistent in UK brands. Many shoppers find UK sizing closer to true volume than US.
- Is a French 90 the same as EU 90?
- No. French sizing is offset by 15 — a French 90 is an EU 75. The under-bust measurement column is the safest reference across both.