G Cup Bras

A G cup bra is a full-bust bra where "G" describes the difference between your bust and band measurements. Because the cup grows with the band, a 32G and a 40G hold very different volumes. G cup bras are built for support, with underwire, wider straps and full cups, and come in every style.

There's no single answer, because the cup is relative to the band — a G cup on a 30 band is much smaller than on a 42 band. In UK sizing the order is D, DD, E, F, FF, G, GG, H, making G a true full-bust cup; US sizing has fewer steps. Always read the size with its band number.

Not exactly. UK sizing uses more cup steps (adding DD, FF, GG), so a UK G sits further along the alphabet than a US G. Many specialist full-bust brands use UK sizing, so check each brand's own chart and convert if needed rather than assuming the letters match.

G cup bras are made across a wide band range, typically from around 30G up through 44G, so the cup suits both smaller and larger frames. The band you need is set by your ribcage measurement, while the G cup reflects your bust-to-band difference.

In UK sizing, GG (double-G) is one step up from G, and H is the step above that. Each is roughly an inch more bust-to-band difference at the same band. If a G cup spills at the top or sides, sizing up a cup is usually the fix — compare our H cup bras.

Sister sizes hold the same cup volume with a different band. If the cup fits but the band is loose or tight, size across: going down a band goes up a cup, and vice versa. For example, 36G is close to 34GG and 38FF. It's the fastest fix when a band feels off.

Measure your band snugly around the ribcage just under the bust, then measure around the fullest part of the bust. The difference gives your cup size. Because sizing varies between brands, use the result as a starting point and check each brand's size chart before ordering.

Look for a firm, supportive band (which does most of the work), underwire that encloses the whole breast and sits flat on the ribcage, wider adjustable straps to spread weight, and full cups or side-support panels. These are what make a full-bust bra comfortable and supportive all day.

Yes. The best sports bras for a G cup combine encapsulation (separate cups) with compression and a wide, firm band to control bounce during high-impact activity. Browse our sports bra range for full-bust styles built to keep you secure and comfortable.

Yes — full-bust strapless bras exist and stay up when they're the right design: a deep, grippy band, silicone lining and often light side boning to support a G cup without straps. The correct band size matters even more than usual, since the band alone carries the support.

Yes. G cup nursing and maternity bras combine drop-down cups for easy feeding with the full-bust support you need — wide straps, a firm band and full cups. They're designed to stay comfortable through the size changes of pregnancy and breastfeeding.

G cup is a specialist size, so the brands that make it well are the full-bust labels that build support into every style. You'll find size-inclusive G cup options across our full-bust and designer edits, chosen specifically for fit and support at larger cup sizes.

Many mainstream retailers stop at DDD or F, so full-bust sizes like G get overlooked despite high demand. That's why specialist full-bust brands and curated collections exist — to carry a real range of G cup styles with the construction that larger cups actually need.

The band should sit snug and level around your body (most of the support comes from here), the underwire should enclose the breast and lie flat on the ribcage, the straps shouldn't dig, and the cups should contain everything without gaps or spillage. If any of those are off, try a sister size.