Select your band and cup size in any system to see the equivalent in US, UK, EU, FR/ES, and IT — plus sister sizes if you'd like to try a different fit.
Cups A through D use the same letter in the US, UK, and EU. Past D, each system keeps adding letters on its own path — so the letter itself stops being a reliable translation, even though the physical size keeps increasing consistently.
| US | UK | EU / FR / IT |
|---|---|---|
| A | A | A |
| B | B | B |
| C | C | C |
| D | D | D |
| DD (or E) | DD | E |
| DDD (or F) | E | F |
| G (or DDDD) | F | G |
| H | FF | H |
| I | G | I |
| J | GG | J |
| K | H | K |
Some US brands additionally label DD as E, DDD as F, and G as DDDD — this converter accepts either spelling.
A sister size is a different band/cup combination with roughly the same cup volume: go one band size down and one cup letter up, or one band size up and one cup letter down. 34B, 32C, and 36A are all sister sizes of each other — useful when your usual size runs out, or the band feels off but the cup fits.
Band size is measurement-based, so it converts consistently across systems (unlike cup letters above).
| US | UK | EU | FR / ES | IT |
|---|---|---|---|---|
| 28 | 28 | 60 | 75 | 0 |
| 30 | 30 | 65 | 80 | 1 |
| 32 | 32 | 70 | 85 | 2 |
| 34 | 34 | 75 | 90 | 3 |
| 36 | 36 | 80 | 95 | 4 |
| 38 | 38 | 85 | 100 | 5 |
| 40 | 40 | 90 | 105 | 6 |
| 42 | 42 | 95 | 110 | 7 |
| 44 | 44 | 100 | 115 | 8 |