Bras don't use the same size logic as the rest of your wardrobe, a bra size is a band and cup measurement, not an alpha or dress size. Enter your band and bust measurements below to calculate yours, shown in US sizing first with the UK and EU equivalents right alongside. Looking for panties instead? See our Panty Size Guide.
Bra Size Calculator
Measuring tips for your bra size
- Band: measure directly underneath your bust, wrapping snugly around your ribcage. Keep the tape level and parallel to the floor.
- Bust: measure around the fullest part of your bust, tape level, wearing a non-padded bra if you can.
- Cup size comes from the difference between the two, not from the bust measurement alone.
Band & Cup Size Reference
Band size in US/UK and EU, plus how the cup letter is read from the difference between your bust and band measurements. Systems match up to a D cup, then diverge.
| Band (in, snug) | US / UK Band | EU Band |
|---|
Cup size, from bust minus band:
| Difference (in) | US Cup | UK Cup | EU Cup |
|---|
Fit Tips for Bras
Numbers alone don't guarantee a good fit. A few things worth knowing before you buy:
About This Tool
Our Bra Size Calculator works from your band and bust measurements to find your band and cup size, since bras use their own sizing logic rather than the site's general alpha sizing used elsewhere.
- Covers US/UK bands 28 to 46 and cups AA to I
- Works from band and bust measurements
- Converts between inches and centimeters
- Shows the full band and cup reference chart alongside your result
How This Tool Works
Measure your band and bust using the guide below.
Choose your preferred units using the in / cm toggle at the top of the tool.
Enter both measurements, then select Calculate My Bra Size.
Check your recommended band and cup size, its UK and EU equivalents, and the fit tips above.