Find your bra size from your underbust and bust measurements, in EU, French, UK and US sizes. Enter your values; the result updates as you type, with the method shown below.
About this calculator
A bra size combines a band size and a cup letter, and the letters differ between European, UK and US systems. This calculator turns two tape measurements into a starting size in each system.
Measure under the bust and around the fullest part of the bust, in centimetres, and enter both values.
When to use it
- Finding a first size before shopping.
- Converting a size from a foreign brand.
- Checking a size after a change in weight.
- Buying online.
How to read the result
Band = underbust rounded to the nearest 5 cm; cup = bust − underbust, with 13 cm for an A and one cup every 2 cm after that.
Sizes vary between brands and styles: use the result as a starting point and adjust after trying on.
Mistakes to avoid
- Measuring over a padded bra.
- Pulling the tape too tight or too loose.
- Assuming the same size fits every brand.
Formula
Band = underbust rounded to 5 cm; cup = bust − underbust (13 cm = A, +2 cm per cup)
Worked example
Underbust 75 cm and bust 90 cm: EU 75B, FR 90B, UK and US 34B.
Frequently asked questions
How do I measure?
Measure snugly under the bust, then at the fullest point, without padding.
Why is my size different between brands?
Each brand cuts a little differently: try on.
Why does my size change between brands?
Each brand cuts differently.
What if I am between two band sizes?
Try both; the band should be firm but comfortable.
Is a UK DD the same as a European E?
They are roughly equivalent.
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Results are estimates for information only. Check important figures with a professional.