Bra size calculator
Two tape measurements, six countries' sizes. Measure over an unpadded bra or bare skin.
Band 32 in, difference 4 in → 4 cup steps.
Sister sizes to try: 28E, 30DD, 34C, 36B
Brands vary. These conversions follow Wacoal's international bra size guide. Another label can run half a size (or a whole size) different, so if the store publishes its own chart, trust that first. All sources
How to measure your bra size
- Band. Wrap the tape snugly around your ribcage just under the bust, level all the way round, and breathe out. Round to the nearest even number of inches.
- Bust. Measure around the fullest part, tape level and loose enough not to compress. Leaning forward slightly helps if you have soft tissue.
- Cup. Subtract band from bust. Each inch is one cup: A, B, C, D, DD, E, F, FF…
Wearing a bra with a padded or moulded cup while measuring adds inches to the bust. Measure in a thin unlined bra.
Why a cup letter isn't a fixed size
A cup letter only counts the gap between bust and band. Drag both and watch the letter, then compare what the same letter means on different bands.
34C
The same C cup on a 38 band holds noticeably more volume than on a 34 band, because the cup is built around a wider ribcage. That's why a 34C often fits like a 36B: one band up, one cup down. Those are sister sizes.
Questions shoppers ask
How do I measure my bra size?
Measure snugly around your ribcage directly under the bust, tape level, and round to the nearest even inch: that is your band. Then measure loosely around the fullest part of the bust. Each inch of difference between the two is one cup: 1 = A, 2 = B, 3 = C, 4 = D, 5 = DD, 6 = E in UK sizing.
Is a UK bra size the same as a US bra size?
Bands match (a UK 34 is a US 34). Cups match up to DD, then split: UK goes E, F, FF, G, while US brands often use DDD, G, H. A UK F is roughly a US G on Wacoal's conversion.
Why does the calculator not add 4 inches to my band?
The old "plus four" method came from rigid fabrics. Modern stretch bands fit best close to your true underbust, which is the method UK fitters and brands like Panache follow. If a band feels tight, try its sister size (one band up, one cup down).
What does 75C mean?
75C is the EU way of writing a UK/US 34C: the band is your underbust in centimetres (rounded to 5 cm), with the same cup letter up to D. In France the same bra is a 90C.
How accurate is a bra size calculator?
It gives a starting size. Breast shape, root width and a brand's cut all change the fit, so try the result and its sister sizes. Signs of a good fit: the band sits level and snug on the loosest hook, the centre gore lies flat, and the cups don't gape or spill.