G cup measurements by band
| Size | Underbust | Bust | Same volume as |
|---|---|---|---|
| 28G | 28 in (71 cm) | 37 in (94 cm) | 26GG and 30FF |
| 30G | 30 in (76 cm) | 39 in (99 cm) | 28GG and 32FF |
| 32G | 32 in (81 cm) | 41 in (104 cm) | 30GG and 34FF |
| 34G | 34 in (86 cm) | 43 in (109 cm) | 32GG and 36FF |
| 36G | 36 in (91 cm) | 45 in (114 cm) | 34GG and 38FF |
| 38G | 38 in (97 cm) | 47 in (119 cm) | 36GG and 40FF |
| 40G | 40 in (102 cm) | 49 in (124 cm) | 38GG and 42FF |
| UK | US | EU / France | Australia |
|---|---|---|---|
| G | I | I | G |
UK G and US G are two sizes apart
| Label | Bust minus band | In UK sizing |
|---|---|---|
| US G | 7 in | F |
| EU G | 7 in | F |
| UK G | 9 in | G |
The UK reaches G later because it fits DD and FF in on the way. If you wear a UK 34G:
- from an American brand you most likely need a 34I,
- from a European brand, a 75I or 75J depending on the brand, and
- from a British brand, 34G, wherever in the world you buy it.
Brands differ in how they letter cups at this level, so check the brand's own chart. The background is in UK vs US bra sizes.
What to look for in a G-cup bra
- The band, correctly fitted. A loose band at this cup size means strap pain and a back that rides up. If in doubt between two bands, the firmer usually serves better.
- Seamed, unlined cups. Most well-regarded G-cup bras are made from three or four panels. They provide depth at the front and lift from below.
- Side support panels or slings.
- A wide band with three or more hooks, and wide straps.
- The right cup shape. At this volume, whether your breasts are narrow and projected or wide and shallow changes which bras fit. See the breast shapes guide.
Moulded and T-shirt bras
They exist in G cups and suit some shapes well. Many people find that a fixed foam cup does not match them at this size, leaving a gap at the top or lifting away at the centre. A spacer-fabric or lightly lined seamed bra gives a smooth line with more adaptable shaping.
Sports bras
Choose a sports bra sold in band and cup sizes. S, M, L sizing cannot hold a G cup securely. See best sports bras for large busts.
Where G cups are sold
The larger high-street chains reach a G in some of their ranges, and many stop there. The widest choice by far is at full-bust brands such as Freya, Panache, Curvy Kate, Elomi and Fantasie, and at retailers that specialise in them. If you are a G on a 28 or 30 band, those specialists are effectively the only source.
A fitting with someone experienced in fuller cups is well worth it. See bra fitting for large busts.
Frequently asked questions
What is a UK G cup in US sizes?
Most commonly a US I. The UK G is a nine-inch difference between bust and band, and American single-letter sizing reaches that step at I.
Is a US G the same as a UK G?
No. A US G is a seven-inch difference, which is a UK F. A UK G is two cup sizes bigger than a US G.
What comes after a G cup in the UK?
GG, then H, HH, J. There is no I cup in UK sizing.
Is a G cup very large?
It is a fuller bust, and how large depends on the band. A 30G holds the same as a 36E. It is a standard size at every UK full-bust brand.
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