Bra conversion

US to UK bra size

Convert a US bra size to UK in one step. Band and cup are shown separately below, since they do not always shift together.

US to UK band size chart

Each US band size and its UK equivalent, with the underbust measurement in centimetres.
US bandUK bandUnderbust (cm)
282858 to 62
303063 to 67
323268 to 72
343473 to 77
363678 to 82
383883 to 87
404088 to 92
424293 to 97
444498 to 102
4646103 to 107
4848108 to 112

US to UK cup size chart

Cup letters by the difference between bust and band, in US and UK.
Bust minus band (in)US cupUK cup
1AA
2BB
3CC
4DD
5DDDD
6DDD / FE
7GF
8HFF
9IG
10JGG
11KH

Bra size is two independent measurements folded into one label: the band comes from the underbust circumference, and the cup comes from the difference between the bust and the band. US and UK both describe the same body, just with different numbering, so the band and cup charts above convert the label without changing the fit.

Band and cup conversions here are checked against the internationally published bra size conversion tables (matching the reference tables in Wikipedia's "Brassiere measurement" article), including Italy's separate small-number band scale. There is no single global standard for bra sizing the way there is for shoes or rings, so treat the chart as a strong starting point and confirm fit in person where possible.

To measure your own band and bust, see how to measure bra size, or use the bra size calculator to get your size from measurements directly.

Common questions

What is a US 34 band in UK?

A US 34 band is a UK 34 band, both fitting an underbust measurement of about 73 to 77 cm.

What is a US DD cup in UK?

A US DD cup is a UK DD cup. Cup letters match up to a D cup, then diverge, so always check the cup column rather than assuming the same letter.

How do I convert a US bra size to UK?

Find your US band in the chart and read across to the UK column for the band, then do the same on the cup table if it is shown. Both are anchored to real body measurements, so the conversion holds regardless of brand.

What if I'm between two band sizes?

Choose the smaller band on the loosest hook. A band that is snug on the loosest setting still has room to tighten as the band stretches with wash and wear.

Last reviewed and updated on July 2, 2026. Band and cup conversion tables are checked against published international bra size conversion charts.