US, UK and EU Bra Size Conversion (Without the Confusion)
You found the perfect bra, but it is sized in UK letters or EU numbers. Here is how the three systems line up so you can shop across them with confidence.
Bra sizing is not standardized worldwide, which is why a bra that fits perfectly can carry three different labels depending on where it was made.
The good news: the conversions are predictable once you know the two places the systems diverge — the band number and the cup lettering.
Band conversion
US and UK band numbers are usually the same (a 34 band is a 34 band). EU and many other European systems use a different number for the same band:
- US/UK 30 → EU 65
- US/UK 32 → EU 70
- US/UK 34 → EU 75
- US/UK 36 → EU 80
- US/UK 38 → EU 85
- US/UK 40 → EU 90
The pattern: EU band = US/UK band step mapped in fives, starting from 65. Each two-inch band step up adds five to the EU number.
Cup conversion is where it gets tricky
US and UK cups agree up to D, then they part ways. The UK system inserts more single letters (DD, E, F, FF, G…), while US sizing leans on doubled and tripled letters (DD, DDD) before moving on.
Here is the common alignment:
- US D = UK D = EU D
- US DD = UK DD = EU E
- US DDD/F = UK E = EU F
- US G = UK F = EU G
- US H = UK FF = EU H
A worked example
Say you wear a US 34DD. The band 34 maps to EU 75. The cup US DD maps to UK DD and EU E. So your equivalents are roughly UK 34DD and EU 75E.
Why you should still confirm with the brand
These conversions get you to the right neighborhood, but individual brands cut their cups and bands slightly differently, and some run small or large.
Use the conversion to pick your starting size, then sanity-check against the brand's size chart and, if the band feels off, reach for a sister size.
When in doubt, re-measure with our at-home guide and work from your actual numbers rather than a label.