Bra Size Calculator

Measure your band and bust and get your bra size in US, UK and EU sizing, plus a sister-size fit tip. Free, private bra size calculator — nothing is uploaded, works right in your browser.

Band (under bust)

Snug around your ribcage, just under the bust.Bust (fullest point)

Around the fullest part, tape level.

Enter both measurements.

How to use the Bra Size Calculator

1
Measure snugly under your bust for the band.
2
Measure around the fullest part for the bust.
3
Enter both in inches or centimetres.
4
See your US, UK and EU size instantly.

Frequently asked questions

How do I measure my band?

Wrap the tape snugly around your ribcage directly under your bust, keeping it level all the way around.

What is sister sizing?

If a size feels off, going down a band and up a cup (or vice versa) keeps a similar cup volume with a different band fit.

Is it accurate?

It's a solid starting estimate — cup and band fit varies by brand and style, so try a couple of nearby sizes.

Tips & discussion

Share a trick, ask a question, or help others get more out of this tool.

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