FF cup measurements by band
| Size | Underbust | Bust | Same volume as |
|---|---|---|---|
| 28FF | 28 in (71 cm) | 36 in (91 cm) | 26G and 30F |
| 30FF | 30 in (76 cm) | 38 in (97 cm) | 28G and 32F |
| 32FF | 32 in (81 cm) | 40 in (102 cm) | 30G and 34F |
| 34FF | 34 in (86 cm) | 42 in (107 cm) | 32G and 36F |
| 36FF | 36 in (91 cm) | 44 in (112 cm) | 34G and 38F |
| 38FF | 38 in (97 cm) | 46 in (117 cm) | 36G and 40F |
| 40FF | 40 in (102 cm) | 48 in (122 cm) | 38G and 42F |
| UK | US | EU / France | Australia |
|---|---|---|---|
| FF | H | H | FF |
A full size, with a confusing name
The doubled letter makes FF look like a variation on F. It is the next rung of the ladder, exactly as far from F as F is from E. The UK sequence here is E, F, FF, G, GG.
Two practical consequences follow:
- If an F is a little small, the next size to try is FF, not G.
- When sister sizing, FF counts as a step. A 34FF goes to 32G on a firmer band and 36F on a looser one.
FF only exists in UK sizing
No other system has an FF. If you see it on a label, the bra is in UK sizes. To buy from a brand that does not use UK sizing, convert first: FF is usually H in both US and European lettering, though brands vary at this point in the range. Check the brand's chart, or use the international bra size chart as a first guide.
What to look for in an FF-cup bra
- A firm, correctly sized band. At this volume the band carries real weight. See how tight a bra band should be.
- Seamed cups. Three or four fabric panels give depth and lift that a single moulded piece struggles to match.
- Side support, to bring tissue forward from under the arm.
- Wider straps and three hooks at the back.
- Wires on ribcage, not on tissue. Press the wire at the side to check.
Where FF cups are sold
FF is around the point where high-street choice begins to thin. The larger chains include it in some core styles, mainly on 32 to 38 bands. Full-bust brands treat it as a mid-range size and offer it across nearly everything they make, from a 28 band upward. If you have been choosing from two or three bras in a mainstream shop, a full-bust retailer will show you dozens.
Not sure about the letter?
FF sounds very large to people who expect D to be the top of the scale. On a 30 band it holds the same as a 34E or a 36DD. The letter rises quickly on a small band without the bust being unusual. Sister sizes for a larger bust shows how the upper letters relate.
Frequently asked questions
Is FF bigger than F?
Yes, by one full cup size. FF is the cup between F and G in UK sizing. It is not a half size or a slightly larger F.
What is a UK FF cup in US sizes?
Most commonly an H. American sizing has no double letters after DD, so the eight-inch cup is labelled with a single letter two places further on.
Is FF the same as G?
No. In UK sizing G is one cup bigger than FF. In European sizing a UK FF is usually labelled H.
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