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Bra Size Converter

Already know your size? Type it in, pick the region it comes from, and see the matching size in US, UK, EU, French, Australian and Japanese sizing, plus the full cup letter sequence for each region.

Last updated:

Band number + cup letter. Japanese sizes may be written cup first (C70).

Enter your values to see the result.
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How to use the Bra Size Converter

  1. Pick the region your current size comes from, for example UK if the label says 32FF.
  2. Type your size: band number plus cup letter (34C, 80D, 12DD or C75 for Japan).
  3. Choose the region to convert to and press Convert.
  4. Read the result and the same size in every other region below it.
  5. Check the cup sequence chart to see where the letters start to differ between countries.

How bra size conversion works

Every bra size has a band (how big around the ribcage) and a cup (how much larger the bust is than the band). Countries label both parts differently, but the underlying sizes line up one to one, so converting means translating the band number and counting the cup steps.

  • Band: US and UK use inches (28, 30, 32…). EU and Japan use centimeters in steps of 5: EU = 60 + 5 × (US − 28) ÷ 2, so 34 becomes 75. France, Belgium and Spain add 15 to the EU band (FR 90). Australia and New Zealand subtract 22 from the US band (AU 12).
  • Cup: count the position of the letter in its own region's sequence, then take the letter at the same position in the target region. The 6th cup is DD in the US and UK but E in EU and France.

Worked example: UK 32FF. The band 32 is the same in the US, EU 70, FR 85, AU 10. FF is the 9th UK cup (AA, A, B, C, D, DD, E, F, FF). The 9th US cup is H and the 9th EU cup is H, so UK 32FF = US 32H = EU 70H = FR 85H = AU 10FF.

Where the cup letters split

Cup stepUSUK / AUEU / FRJapan (approx.)
1–5AA, A, B, C, DAA, A, B, C, DAA, A, B, C, DA, B, C, D, E
6DDDDEF
7DDD / FEFG
8GFGH
9HFFHI
10IGIJ
11JGGJK

Because the sequences drift apart, the same letter means different volumes in different countries: an F cup is the 7th step in the US, the 8th in the UK and the 7th in Europe. Always convert by position, never by letter.

Tips for buying a converted size

  • Read the label region: many bras carry several sizes on one tag. A tag reading "34DD / 75E / 90E" lists UK, EU and FR sizes.
  • Japanese and some Asian brands often run one cup letter higher and slightly snugger in the band; if in doubt, try the next band up.
  • US brands vary after DD: some call the 7th cup DDD, others F. If a US brand uses F, it is the same as DDD in this chart.
  • Not the right fit? Use the Bra Sister Size Calculator to find sizes with the same cup volume on a different band, or measure yourself with the Bra Size Calculator.

Frequently asked questions

Are US and UK bra sizes the same?

The band numbers are the same and cups match from AA to DD. After DD they split: the US goes DDD (or F), G, H, I, while the UK goes E, F, FF, G, GG. So a UK 34E is a US 34DDD, and a UK 34F is a US 34G.

How do I convert a European bra size to US?

EU bands are in centimeters in steps of 5: 65 = 30, 70 = 32, 75 = 34, 80 = 36, 85 = 38. EU cups go A, B, C, D, E, F, G without doubled letters, so EU 75E is US 34DD and EU 75F is US 34DDD.

How do French bra sizes differ from EU sizes?

French, Belgian and Spanish bands are 15 higher than EU bands: FR 90 is EU 75 and US 34. The cup letters are the same as EU, so FR 90C equals EU 75C and US 34C.

How do Australian bra sizes work?

Australia and New Zealand use dress-size style bands: subtract 22 from the US band, so US 34 is AU 12 and US 36 is AU 14. Cup letters follow the UK sequence with DD, E, F, FF.

Why are Japanese cup letters one size bigger?

Japanese cups are measured in 2.5 cm steps starting lower than European cups, so the same cup volume usually gets the next letter up: a US 34B is about a Japanese C75. Japanese sizes are written cup first.

Will a converted size fit exactly the same?

Not always. Conversions follow the standard charts, but brands cut differently, especially for large cups. Use the converted size as a starting point and try a sister size if the band or cup feels off.

Are all the tools on FreeToolCabin tested for quality and accuracy?

Yes! Every tool on our site undergoes automated Q/A testing in real browser environments to ensure high precision, correct output, and zero errors. If you happen to spot a bug or have a suggestion, please contact us at [email protected] and our team will review it right away.

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