Calculate your bra size from measurements or convert an existing size across US, UK, EU, French, and Japanese systems. This calculator also shows sister sizes, which are alternate band and cup combinations that may fit better depending on the brand. Measure on bare skin or over a thin unpadded bra for the most accurate results. No account needed.
Measure on bare skin or over a thin unpadded bra. Exhale normally before reading the tape.
| US/UK Band | EU Band | FR Band | Underbust (in) | Underbust (cm) |
|---|---|---|---|---|
| 30 | 65 | 80 | 26-27 | 66-68 |
| 32 | 70 | 85 | 28-29 | 71-73 |
| 34 | 75 | 90 | 30-31 | 76-78 |
| 36 | 80 | 95 | 32-33 | 81-83 |
| 38 | 85 | 100 | 34-35 | 86-88 |
| 40 | 90 | 105 | 36-37 | 91-94 |
| 42 | 95 | 110 | 38-39 | 96-99 |
Wrap the tape snugly around your ribcage, directly under your bust. Keep the tape level and breathe normally.
Wrap the tape around the fullest part of your bust, keeping it level across your back. Do not pull tight.
Type your underbust and bust measurements above. The calculator will determine your band and cup size instantly.
Victoria\'s Secret often measures differently in-store. Their sizing tends to push customers into larger band and smaller cup combinations.
French brands (Simone Pérèle, Chantelle) add 15cm to the underbust measurement. A US 34 is roughly a FR 90.
Japanese lingerie cup letters run 1-2 sizes smaller than US equivalents. A JP C cup is closer to a US A or B cup.
Sister sizes are bra sizes with the same cup volume but different band lengths. For example, 34C, 32D, and 36B all hold roughly the same cup volume. If your usual size feels wrong in a particular brand, trying a sister size can improve the fit without changing the cup volume.
US and UK sizing diverge after D cup. In US sizing, the progression goes D, DD, DDD (or F), G, H. In UK sizing, it goes D, DD, E, F, FF, G, GG, H. The UK system has more granular steps in larger cup sizes, making it slightly more precise.
EU band sizes are measured in centimeters and start at 60 (equivalent to US 28). Common sizes like 75, 80, and 85 correspond to US 34, 36, and 38. The cup letter system is the same across EU countries, but the band numbers differ from US and UK.
Either works. Measuring in centimeters gives you a more precise number, which can help when converting between systems. If you measure in inches, our calculator handles the conversion automatically.
French sizing uses a different measurement point. While US and UK sizes round the underbust measurement to the nearest even number, French sizing adds approximately 15cm to the actual underbust measurement. This is a convention, not a different fit.