A UK F cup means your bust is about 7 inches bigger than your band. In US sizing that same cup is called G (or DDDD at some brands). Confusingly, a few US brands use F to mean DDD, which is one cup smaller. So before you buy an F, check which system the brand uses.
| Band 34 | Underbust over 32 and up to 34 inches (81–86 cm). We round your underbust up to the next even number. |
|---|---|
| Cup F | Bust about 7 inches bigger than the band: roughly 40½ to 41½ inches (103–105 cm) around the fullest part. |
| Sister sizes | 32H (UK 32FF) (tighter band) and 36DDD (UK 36E) (looser band). Full diagonal: 28J (UK 28GG), 30I (UK 30G), 32H (UK 32FF), 34G (UK 34F), 36DDD (UK 36E), 38DD, 40D, 42C, 44B, 46A, 48AA. |
| Same size abroad | US 34G · UK 34F · EU 75G · French 90G · Australia / NZ 12F |
Brands measure differently, and some US brands add inches to the band. Use these numbers as a starting point, then check the fit. Calculate your own size · See every sister size · Convert another size
F cup in every system
| Label | Cup difference | US equivalent | UK equivalent |
|---|---|---|---|
| UK or AU F | 7 in | G (DDDD) | F |
| EU or French G | 7 in | G (DDDD) | F |
| US “F” (at brands that use it for DDD) | 6 in | DDD | E |
UK-sized brands such as Curvy Kate show both labels on their US sites, for example “28F (US 28G)”. Our bra size converter converts any size.
UK F cup sizes across bands
| UK size | US size | Bust (approx. in) | Sister sizes (US) |
|---|---|---|---|
| 28F | 28G | 35 | 30DDD |
| 30F | 30G | 37 | 28H, 32DDD |
| 32F | 32G | 39 | 30H, 34DDD |
| 34F | 34G | 41 | 32H, 36DDD |
| 36F | 36G | 43 | 34H, 38DDD |
| 38F | 38G | 45 | 36H, 40DDD |
Our guides to 30F, 32F and 36F cover the most searched F sizes.
Why F means two things in the US
US sizing follows D, DD, DDD, then usually G. Some brands filled the gap with F and use it for the cup straight after DD, the same cup most call DDD. UK sizing goes D, DD, E, F, so its F is the seventh step. When you see “F” on a US label, check the brand’s size chart for the inch measurement or its UK equivalent.
How to find F cup bras that fit
- Shop UK-sized brands for the widest F range, especially in smaller bands.
- Use your measured size, not your old one. Measure snugly under the bust and loosely around the fullest part; 7 inches is a UK F.
- Look for supportive styles: seamed full cups, balconettes with side support and banded underwires.
- Try sister sizes when the band fits but the cups don’t, or the reverse.
Shop F cup bras
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UK F cup bras
Look for UK sizing on the label or size chart.
Search Amazon for uk f cup bras (opens in a new tab, affiliate link) -
US G (UK F) bras
The same cup in US labels.
Search Amazon for us g (uk f) bras (opens in a new tab, affiliate link) -
F cup sports bras
Band-and-cup sized sports bras support best.
Search Amazon for f cup sports bras (opens in a new tab, affiliate link)
Results are Amazon’s, not our picks. Check the size range, the return policy and the features above before you buy.
F vs E vs FF
On the same band, each UK step is about an inch: E is 6, F is 7, FF is 8. Our E cup guide covers the step before, and the G cup guide explains where the US and UK letters line up again.
