Bra Size Calculator
Find the right bra size by measuring the bust and underbust.
Tip: Measure without a bra, with the tape horizontal (not tight), breathing normally. Take the measurement in front of a mirror to make sure the tape is level.
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About this digital tool
The bra size calculator helps you find the right size using two measurements: the circumference under the bust (underbust) and the circumference of the bust at its fullest point. The difference between them determines the cup, while the underbust determines the band.
The result is given in the system you choose (EU, US, UK, FR or IT), with neighbouring sizes (sister sizes) you can try when a model doesn't fit well. Sizes differ slightly from brand to brand, so the result is a starting point and not a guarantee; always try the bra on. For a more accurate measurement, measure without a bra or with a thin one, with the tape horizontal and not tight. If you have persistent pain, consult a doctor.
How to use
- Measure the underbust circumference (under the bust, in cm)
- Measure the bust circumference (fullest point, in cm)
- Choose the system (EU, US, UK, FR, IT)
- See the size: band + cup
- See sister sizes and fitting tips
Frequently asked questions
How do I measure my size?
Measurement 1 (band): the circumference directly under the bust. Measurement 2 (bust): the circumference at the fullest point of the chest. Cup = bust - band (each cm = 1 cup size: 1cm=AA, 2=A, 4=B, 6=C, 8=D).
Why do sizes differ between brands?
There is no universal standard. The EU uses cm directly (75B, 80C), the US/UK use inches + letters (34B, 36C). Even within the same system, cuts differ between manufacturers.
What is 'sister sizing'?
Sizes with the same cup volume but different bands. E.g., 75D, 80C and 85B have a similar cup volume. If the band is right but the cup isn't, try a sister size.
How do I measure myself for a bra size?
Measure the circumference under the bust (underbust) keeping the tape horizontal, then the circumference at the fullest point of the chest (bust). The difference between them gives the cup size.
What are sister sizes?
They are alternative sizes with the same cup volume, e.g. 75C and 70D. They help when your main size is out of stock or fits slightly loose or tight.