UK to US Bra Size Conversion
UK and US bra sizes use the same band numbers and the same cups up to D. After D they split: UK DD is US DD or E, UK E is US DDD or F, UK F is US G, and UK FF is US H. Keep the band number the same and convert only the cup letter.
Convert UK and US sizes
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Converted size
Brands do not all follow the same chart. Treat converted sizes as a starting point and check the brand’s own size guide.
UK and US cups side by side
| UK cup | US cup | Bust − band |
|---|---|---|
| A | A | 1" |
| B | B | 2" |
| C | C | 3" |
| D | D | 4" |
| DD | DD/E | 5" |
| E | DDD/F | 6" |
| F | G | 7" |
| FF | H | 8" |
| G | I | 9" |
| GG | J | 10" |
| H | K | 11" |
| HH | – | 12" |
| J | – | 13" |
| JJ | – | 14" |
| K | – | 15" |
Why the letters split after D
Both systems count cups in one-inch steps, but they name the larger steps differently. UK sizes use doubled letters (DD, FF, GG, HH, JJ). US sizes often use DD and then DDD, or E and F, and labels vary between brands. That is why a UK F and a US F are not the same cup.
Common UK to US conversions
| UK size | US size |
|---|---|
| 32DD | 32DD/E |
| 32E | 32DDD/F |
| 32F | 32G |
| 32FF | 32H |
| 34DD | 34DD/E |
| 34E | 34DDD/F |
| 34F | 34G |
| 34FF | 34H |
| 36DD | 36DD/E |
| 36E | 36DDD/F |
| 36F | 36G |
| 36FF | 36H |
| 38DD | 38DD/E |
| 38E | 38DDD/F |
| 38F | 38G |
| 38FF | 38H |
Measuring for UK or US sizes
Both systems use the same tape method on this site: snug underbust rounded to an even inch for the band, one cup per inch of bust difference. Use the calculator and choose UK or US.
Frequently asked questions
Are UK and US bra sizes the same?
The bands are the same and the cups match from AA to D. From the cup after D they use different letters, so a UK 34F is a US 34G. Always convert the cup if your size is above D.
What is a UK DD in US sizes?
A UK DD is a US DD, also sold as E. The band number stays the same, so a UK 34DD is a US 34DD or 34E.
What is a UK E cup in US sizes?
A UK E is the next cup after DD. In US sizes it is usually labelled DDD or F. So a UK 36E is a US 36DDD or 36F.
What is a UK F in US sizes?
A UK F cup is a US G cup. A UK FF is a US H, and a UK G is a US I. The band number does not change.
Why does my US bra say DDD and another says F?
Both labels are used in US sizing for the same step after DD. Brands choose different names, which is one reason to check each brand’s own chart.
Do I measure differently for UK sizes?
No. The tape method is the same for UK and US sizes on this site. Only the letters used for larger cups differ, so measure once and then read the size in whichever system the brand uses. The calculator shows both side by side.
Last updated: October 15, 2026