Bra sizes combine a band number (around the ribcage) and a cup letter. The band converts cleanly between countries. The cup letter is where it gets confusing.
Band size conversion
| UK | US | EU |
|---|---|---|
| 30 | 30 | 65 |
| 32 | 32 | 70 |
| 34 | 34 | 75 |
| 36 | 36 | 80 |
| 38 | 38 | 85 |
| 40 | 40 | 90 |
UK and US band numbers are the same. EU bands are in centimetres, in steps of 5.
Cup letters
Cups A to D match across the UK, US and EU. After D, brands diverge: UK sizes use DD, E, F, FF, G, while US brands may use DD, DDD or other labels, and some use "E" in place of DD. For that reason, the label is not enough above a D. Always check the brand's own chart.
Sister sizes
If the band feels loose but the cups fit, try one band size down and one cup size up (for example 36C becomes 34D). The cup volume stays about the same.
Signs of a good fit
- The band sits level around your back and stays put, and most of the support comes from the band, not the straps.
- The centre panel lies flat against your chest.
- Breast tissue sits in the cups without spilling or leaving gaps.
- You can fit two fingers under the band, but no more.
Brands and styles fit differently, so a professional fitting is helpful. For a clothing size guide, see how to measure yourself.
Converting clothing sizes too?
Use the free converter to switch between UK, US and EU.
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