Bra Size Calculator
Use our free Bra Size Calculator to find your perfect fit with instant US, UK, EU & AU size conversion
How to Measure Your Bra Size
Measure Your Band
Wear a non-padded bra or no bra. Wrap a measuring tape firmly (but not tight) around your ribcage, directly under your bust. Round to the nearest whole number, then to the nearest even number.
Measure Your Bust
Wrap the measuring tape loosely around the fullest part of your bust (usually at nipple level). Don't compress the tissue. Round to the nearest whole number.
Enter Measurements Above
Input both measurements into our calculator to get your exact bra size in multiple international sizing systems, plus sister size recommendations.
Signs Your Bra Doesn't Fit
- ⚠️ The band rides up in the back. Try a smaller band size
- ⚠️ Straps dig into shoulders. The band is not providing enough support
- ⚠️ Straps slip off. Try a smaller band or adjusted strap style
- ⚠️ Cups gap or wrinkle. Try a smaller cup size
- ⚠️ Cups overflow or create a double-bust look. Try a larger cup size
- ⚠️ Underwire pokes or sits on breast tissue. The size or shape is wrong
- ⚠️ Center gore does not lay flat. Try a larger cup size
Bra Size Chart (US)
| Difference | Cup Size |
|---|---|
| 0" | AA |
| 1" | A |
| 2" | B |
| 3" | C |
| 4" | D |
| 5" | DD/E |
| 6" | DDD/F |
| 7" | G |
| 8" | H |
Frequently Asked Questions
Wrap a measuring tape firmly around your ribcage, directly under your bust. The tape should be snug but not tight. Round to the nearest whole number, then round to the nearest even number for your US/UK band size.
Wrap the measuring tape loosely around the fullest part of your bust, usually at nipple level. Do not compress the tissue. The tape should be comfortable, not tight. Round to the nearest whole number.
Sister sizes are bra sizes that have the same cup volume but different band sizes. For example, 34C has the same cup volume as 32D and 36B. This is helpful when your exact size isn't available or when you're between sizes.
Different countries use different sizing standards. US and UK use inches-based systems with different cup progressions. EU and FR use centimeter-based band sizes. Our calculator provides instant conversions between all major sizing systems.
Your bra size can change due to weight fluctuations, hormonal changes, pregnancy, and aging. It's recommended to remeasure every 6-12 months or whenever you notice fit issues.
If you're between band sizes, try the smaller band size first (it will stretch over time). If you're between cup sizes, try the larger cup. You can also try sister sizes for a better fit.
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