Bra Size Calculator
Find your correct bra size in US and UK sizing from your band and bust measurements. Includes how-to measuring guide.
inches
inches
US Bra Size
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UK Bra Size —
Cup Size —
How to Use This Calculator
- Measure snugly around your ribcage just below your bust for the Band Measurement.
- Measure around the fullest part of your bust (wearing an unpadded bra) for the Bust Measurement.
- The calculator shows your US and UK bra size and cup size.
Formula
Band Size = Band Measurement (rounded up to nearest even number)
Cup Difference = Bust Measurement − Band Size
1" = A, 2" = B, 3" = C, 4" = D, 5" = DD, 6" = DDD ...
Example
Band measurement 32", bust measurement 36".
- Band Size = 32
- Cup Difference = 36 − 32 = 4" = D cup
- Bra Size = 32D (US) / 32D (UK)
Frequently Asked Questions
- Use a soft measuring tape. Measure snugly around your ribcage just below your bust for the band size. Then measure around the fullest part of your bust for the bust measurement.
- Cup size is the difference between bust measurement and band size. Each inch of difference corresponds to a cup size: 1"=A, 2"=B, 3"=C, 4"=D, 5"=DD, etc.
- Band sizes are the same in US and UK. Cup sizes differ starting at DD: US uses DD/DDD/DDDD, while UK uses DD/E/F/FF/G/GG/H.
- If your measurement is odd, round up to the nearest even number. For example, a 33" ribcage becomes a 34 band. Some fitters add 4" to the measurement for looser fit.