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UK vs US bra sizes: where the cups split

Updated 18 September 2026. 6 minute read.

Bands: the easy part

UK and US bands are both in inches and use the same numbers. Continental Europe and Japan use centimetres in steps of 5. France, and brands that follow French labelling, add 15 to the European number. Australia and New Zealand use dress sizes.

The classic band mistake is French. FR 90 is a 34, not a 40, and anyone who picks a French bra by their EU number gets a band three sizes too small: FR 75 is a UK 28.

Cups: where UK and US split

UK cups double up letters as they go: D, DD, E, F, FF, G, GG, H, HH, J. The common US sequence runs D, DD, DDD, G, H, I, J. Both add one cup step per label, so the same position in the sequence is the same cup, under a different name.

Read across the UK F row: it is a US G. So a 34F from a UK brand and a 34F from a US brand that uses single letters are different bras, one cup apart.

US brands disagree with each other

The US column above is the common sequence, not a standard. Among the brand size runs we have checked, 13 follow D with DD then DDD (Bali, Cleo by Panache, Elomi, Fantasie, Harper Wilde, Intimissimi, lululemon, Natori, Panache, Playtex, Savage X Fenty, Vanity Fair and Wacoal), 5 follow D with E then F (Anita, Chantelle, CUUP, Nike and ThirdLove), 2 follow D with DD then F (Glamorise and SKIMS), 1 follow D with E/DD then F (Le Mystere), and 1 follow D with E/DD then F/DDD (Montelle). Each row below lists one brand's labels in the order it sells them, starting at D.

The letter F shows the problem. At a brand that goes D, E, F it is the second cup after D. At a brand that goes D, DD, F it is also the second. In UK labelling F is the third. And at a brand that uses DDD, there is no F at all. The position in the brand's own list is what carries across brands; the letter does not.

UK brands sold in North America

Cleo by Panache, Elomi, Fantasie, Le Mystere, Panache and Pepper let you switch between US and UK labels on their US sites, and the pairs they show match the chart above: US DDD is UK E, US G is UK F, US H is UK FF, US I is UK G.

Curvy Kate takes the other route: its US site lists every bra in UK sizing and offers a converter beside it. Either way it is one bra under two names. A department store or marketplace listing may not say which labelling it uses. If the size run includes FF, GG or HH, it is UK. If it includes DDD, it is US.

EU, French, Australian and Japanese cups

• EU and FR use single letters with no doubles: D, E, F, G, H. Brands do not agree on the upper end. Freya converts UK G to EU I, while Curvy Kate skips the letter I and converts UK G to EU J. Above F, check the brand's own chart.
• Australia and New Zealand follow UK cup letters on both charts, with dress-size bands: a 34F is a 12F.
• Japan runs one letter higher for the same cup (UK B is JP C), uses centimetre bands like the EU, and usually writes the cup first: C75 instead of 75C.