A bra size has two parts, the band number and the cup letter, and both change from country to country. A 34DD in the United Kingdom is a 75E in Europe, a 90E in France and a 12DD in Australia. This converter does the translation in one step: choose the country your size is in, enter the band and cup, and it shows the same size in the six common systems.
How to use the bra size converter
- Select the system your current size is written in (for example UK).
- Enter the band number, the figure before the letters, such as 34 in 34DD.
- Enter the cup letter(s), such as DD. US shoppers can type E for DD and F for DDD.
- Read the six results. If you do not know your size yet, use the bra-size-calculator first.
Conversion formulas
French band = EU band + 15
Australian band = UK band − 22
Japan band = EU band
US band = UK band
Cup letters are the harder part. The UK, the US and Australia all name their cups differently after D, Europe and France use a letter for every 2 cm step, and Japan uses a letter for every 2.5 cm step. The Australian column follows the Wikipedia scale and Berlei’s centimetre chart (DD, E, F, G, H with no double letters after DD); the UK column keeps FF, GG and HH. The tables below were generated by the same lookup the calculator uses.
Band sizes
| UK / US | EU | France / Spain | Australia | Japan |
|---|---|---|---|---|
| 28 | 60 | 75 | 6 | 60 |
| 30 | 65 | 80 | 8 | 65 |
| 32 | 70 | 85 | 10 | 70 |
| 34 | 75 | 90 | 12 | 75 |
| 36 | 80 | 95 | 14 | 80 |
| 38 | 85 | 100 | 16 | 85 |
| 40 | 90 | 105 | 18 | 90 |
| 42 | 95 | 110 | 20 | 95 |
| 44 | 100 | 115 | 22 | 100 |
| 46 | 105 | 120 | 24 | 105 |
| 48 | 110 | 125 | 26 | 110 |
Cup sizes (from D upwards the systems diverge)
| UK | Australia | US | EU / France | Japan (nearest JIS step) |
|---|---|---|---|---|
| C | C | C | C | D |
| D | D | D | D | E |
| DD | DD | DD/E | E | E |
| E | E | DDD/F | F | F |
| F | F | G | G | G |
| FF | G | H | H | H |
| G | H | I | I | I |
| GG | I | J | J | I |
| H | J | K | K | — |
| HH | K | L | L | — |
| J | L | M | M | — |
Worked example
A shopper in the UK wears a 34DD and is buying from a French site.
- Band: EU = 60 + 2.5 × (34 − 28) = 75, then French = 75 + 15 = 90.
- Cup: UK DD sits in the same step as the European E.
- Result: 90E in France, 75E in Europe, 12DD in Australia and 34DD/E in the US.
Why a conversion is only a starting point
- Brands cut differently. Even in one country, a 34B from two makers can fit differently.
- Letters after D are not standardised. Some US brands use DDD, others F; some UK brands use FF, others skip it.
- Japan uses its own steps. The JIS table adds a letter every 2.5 cm, so there is no one-to-one match with Europe. The Japanese column is the nearest step, so a Japanese brand’s own table is the final word.
- Sister sizes keep the same cup volume in a neighbouring band; the Sister Size Calculator shows them.
If you want to start from measurements instead, use the Band Size Calculator and the Cup Size Calculator, which follow the European standard EN 13402. Always try a bra on when you can; this page is general sizing information and not a professional fitting.
Sources
Every figure above comes from these pages, read directly on the dates shown.
- Fantasie — size guide: international band and cup conversion — checked 2026-10-15
- Brava Lingerie — bra size chart and converter (Australia) — checked 2026-10-15
- Wikipedia — Brassiere measurement — checked 2026-10-15
- Sizely — bra size conversion chart (band table cross-check) — checked 2026-10-15
- Berlei (Rebel) — Australian bra size guide in centimetres — checked 2026-10-15
- HugKum — JIS bra size table (Japanese cups by bust − underbust) — checked 2026-10-15
Frequently asked questions
How do I convert a US bra size to UK?
The band number is the same, because both countries use inches. The cups agree up to DD. After that the US adds DDD (also written F) where the UK has E, and the US G where the UK has F. So a US 34DDD is a UK 34E.
How do I convert a UK bra size to EU?
Convert the band by the rule EU = 60 + 2.5 × (UK − 28), so UK 34 becomes EU 75. Cup letters match through D, then the European run skips the doubled letters: UK DD is EU E, UK E is EU F, and so on.
What is the French bra size?
French and Spanish band numbers run 15 above the European number. EU 75 is French 90. The cup letters are the same as the European ones.
Why do charts give different answers?
There is no single worldwide standard for cup letters beyond D, and brands apply their own. This converter follows published charts from Fantasie, Brava and Wikipedia’s summary, and flags where they disagree. Always trust a brand’s own chart for that brand.
Is the Japanese cup the same as the European cup?
No. The Japanese JIS table starts at A for a 10 cm difference between bust and underbust and adds a letter every 2.5 cm, while the European standard adds a letter every 2 cm from AA at 10–12 cm. The converter matches each European cup to the nearest Japanese step, so the letters run about one ahead (European C is Japanese D). Japan writes the cup before the band, for example D75. See also Japanese Bra Size Calculator.