30F Bra Size, Fully Explained
Also written 30G: 30F is the UK label and 30G the US one. Same cup, same volume, different ladder.
30F is a small band carrying a genuinely full bust, the combination mainstream stores serve worst. The band exists mostly in specialist and UK full-bust ranges, and it matters: on a 30 frame this volume needs real anchorage, and a sister-size-up compromise band gives up exactly the support this size depends on.
30F in every sizing system
| US | UK | EU | FR | AU | JP | KR |
|---|---|---|---|---|---|---|
| 30G | 30F | 65G | 80G | 8F | H65 | H65 |
Sister sizes of 30F
Each sister holds roughly the volume of 30F on a different band. Band riding up in a 30F? Try 28H. Band digging painfully? The other direction.
How 30F compares, visually
Circle areas scale with estimated cup volume: 30F ≈ 1995 cc per cup, roughly 1.8 kg of tissue per side at typical density. Model documented on the weight page.
Is 30F big?
Is 30F big? By chart position yes, it sits in the fuller third, though on a 30 band the projection reads differently than the same letter would on a wider frame. More usefully: this is the range where band quality and cup engineering decide daily comfort, which deserves the attention the "is it big" question usually absorbs.
Shopping notes for 30F
Confirm the size first: two minutes with the calculator beats inheriting a label. Then let the brand decoder translate 30F into each brand's cut, since the same tag runs shallow at mall brands and deep at UK houses, where this size is core range rather than an afterthought. If 30F passes the band checks but the cup misbehaves, that is usually shape, not size.
Frequently asked questions
Last updated August 2026.