A US G cup means your bust measures about 7 inches more than your band. In UK sizing that same cup is called F. A UK G cup is bigger: 9 inches, which US brands label I.
US G vs UK G
The letter G means two different cups depending on where the bra comes from. US and UK sizing agree up to DD, then split:
| Cup difference | US label | UK label | EU label |
|---|---|---|---|
| 6 in | DDD | E | F |
| 7 in | G (or DDDD) | F | G |
| 8 in | H | FF | H |
| 9 in | I | G | I |
| 10 in | J | GG | J |
Curvy Kate’s US storefront shows this directly: its bras are listed in UK sizes with labels like “28F (US 28G)” and “28G (US 28I)”. If you measure as a US 34G and order a UK 34G, you’ll get cups two sizes too big. Our bra size converter handles the conversion for any size.
Why US sizing jumps from DDD to G
Most US brands run D, DD, DDD, then G, skipping E and F altogether. Some, including Victoria’s Secret and ThirdLove, also call the cup after DDD “DDDD”. All of these labels mean the same 7-inch cup. Our DDD bra size guide explains the step before.
US G cup sizes across bands
| US size | UK size | Bust (approx.) | Sister sizes (US) |
|---|---|---|---|
| 30G | 30F | 37 in | 28H, 32DDD |
| 32G | 32F | 39 in | 30H, 34DDD |
| 34G | 34F | 41 in | 32H, 36DDD |
| 36G | 36F | 43 in | 34H, 38DDD |
| 38G | 38F | 45 in | 36H, 40DDD |
The underbust follows the band: just over 32 up to 34 inches for a 34 band, and so on. A 34G holds about the same volume as a 36DDD or a 32H. The sister size calculator lists the full family.
How do you know you’re a G cup?
- Measure snugly around your ribcage under your bust. Round up to the next even number.
- Measure around the fullest part of your bust with the tape relaxed. Some retailers suggest leaning forward slightly to find the fullest point, which can help if your breasts are soft.
- Subtract band from bust. 7 inches is a US G (UK F). 9 inches is a US I (UK G).
The guide to measuring your bra size shows where to hold the tape.
How should a G cup bra fit?
- Band: firm and level. It carries most of the weight, so it matters more at G than at B.
- Cups: tall and deep enough to hold everything. Check under your arm.
- Wires: wide enough to sit behind your tissue at the sides.
- Center gore: flat on your breastbone. If it lifts, the cups are too small or too shallow.
- Straps: wide and padded, set so they don’t dig.
The bra fit checker can help when the fit isn’t right.
Where to find G cup bras
General US stores often stop at DDD or carry G in few styles. Brands focused on fuller busts make G cups as standard. Freya’s US site describes a range up to O in US letters, and those brands make many more shapes at G. Look for seamed cups, side support panels and three or more hooks. Our bras for large breasts guide covers which features matter and why.
Shopping for G cups
Affiliate links-
US G cup bras
Search in US letters, then confirm the brand’s chart uses US sizing.
Search Amazon for us g cup bras (opens in a new tab, affiliate link) -
UK F cup bras
The same cup in UK labels. Many UK brands sell on Amazon.
Search Amazon for uk f cup bras (opens in a new tab, affiliate link) -
G cup full coverage bras
Higher cups and side panels for daily support.
Search Amazon for g cup full coverage bras (opens in a new tab, affiliate link) -
G cup sports bras
Separate cups, a hook-and-eye band and wide straps.
Search Amazon for g 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.
