Bra Size Conversion Guide: US, UK, EU, France and Japan Explained
Why a 34D is not the same cup in the US, UK and EU, how to measure band and cup at home, and a conversion chart for buying bras from overseas retailers.
Bra sizing across borders fails for a specific reason: every system agrees that the band comes first and the cup comes second, but they disagree on how to count both. A UK 34DD, a US 34DD and a EU 75E can be the same bra, or three different bras, depending on the brand. If you have ever ordered from a UK retailer like Bravissimo or Freya and received something two cups off, this is why. Here is how each system works and how to move between them without guessing.
Measure first
Do this in a non-padded bra, standing straight, tape level and snug.
Band: Measure directly under the bust, where the band sits, with the tape tight enough to stay in place. Round to the nearest whole centimeter. Take the measurement again after exhaling; the smaller number is the one to use.
Bust: Measure around the fullest part, tape level, not compressing. Round to the nearest centimeter.
Then use the bra size calculator, which takes those two numbers and returns US, UK, EU, FR and JP sizes together. If you want to understand the result rather than just read it, keep going.
How each system counts the band
| System | Band label | What it means |
|---|---|---|
| US / UK | 30, 32, 34, 36… | Inches. Modern fitting: underbust measurement in inches, rounded to nearest even number. Older “+4” method adds four inches and is why many people wear too-large bands. |
| EU (Germany, Italy, Netherlands, Scandinavia) | 65, 70, 75, 80… | Centimeters, underbust, rounded to nearest 5. |
| France / Spain / Belgium | 80, 85, 90, 95… | EU band + 15. A FR 90 is an EU 75 is a US/UK 34. |
| Italy (traditional) | 1, 2, 3, 4… | EU 65 = 1, 70 = 2, 75 = 3, and so on. |
| Japan / Korea | 65, 70, 75… | Same as EU centimeters. |
| Australia / NZ | 8, 10, 12, 14… | Dress-size style: AU 10 = UK 32, AU 12 = UK 34. |
Band conversion is mechanical: 32 in = 70 cm = FR 85 = IT 2 = AU 10. The problems are in the cup.
How each system counts the cup
The cup letter represents the difference between bust and underbust. Each step is one inch (2.5 cm) in US/UK and roughly 2 cm in EU. But the letters diverge after D:
| Difference | US | UK | EU/JP | France |
|---|---|---|---|---|
| 1 in / 2.5 cm | A | A | A | A |
| 2 in / 5 cm | B | B | B | B |
| 3 in / 7.5 cm | C | C | C | C |
| 4 in / 10 cm | D | D | D | D |
| 5 in / 12.5 cm | DD (or E) | DD | E | E |
| 6 in / 15 cm | DDD (or F) | E | F | F |
| 7 in / 17.5 cm | G | F | G | G |
| 8 in / 20 cm | H | FF | H | H |
| 9 in / 22.5 cm | I | G | I | I |
| 10 in / 25 cm | J | GG | J | J |
The UK system uses double letters (DD, E, F, FF, G, GG, H, HH, J, JJ, K), so it moves through the alphabet slowly. The US system is inconsistent: some brands go D, DD, DDD, G (Victoria’s Secret, Bali); others go D, DD, E, F, G (Wacoal US, Natori). The EU system is the cleanest: one letter per step, no doubles.
Practical consequence: a UK F is a US DDD/G is an EU F. A UK G is a US I. A US DDD from one brand is a US F from another. Reading the letter alone is not enough; you need to know which brand’s alphabet you are looking at.
Sister sizes
If you go down a band size, go up a cup letter to keep the same cup volume, and vice versa. 34C, 32D and 36B all hold the same volume; they differ in band length. This matters when converting: EU bands step in 5 cm, US/UK in 2 inches (5.08 cm), so they track closely, but a body measuring 77 cm underbust is a 75 in EU rounding and a 30 or 32 in US/UK depending on the brand’s rounding. If the converter puts you between two bands, use sister sizing to decide: tighter band and larger cup for support, looser band and smaller cup for comfort.
Where brands deviate from the chart
- Victoria’s Secret, Aerie, Gap: US sizing with the old +4 band method baked into their fit. Many customers measuring a 30 inch underbust wear a VS 34.
- UK brands (Panache, Freya, Curvy Kate, Bravissimo): true-to-measurement bands and the UK double-letter cup scale. If you measure 32 underbust, the 32 will fit snugly, as intended.
- German and Polish brands (Anita, Triumph, Ewa Michalak): EU sizing, firm bands. Ewa Michalak bands run notably tight; many size up a band.
- Japanese brands (Wacoal Japan, Triumph Japan): EU-style numbers but cups start at A for a 10 cm difference, so a Japanese C is roughly a US/UK B. Japanese sizing runs about one cup smaller in effect.
- Uniqlo: uses S/M/L for wireless bras across all markets, mapped to a 65–70 to 80–85 band range. Check the specific band range on the product page rather than assuming; the Uniqlo clothing size guide covers how their letter sizes map.
Converting a size you already wear
If you know your size in one system and want to order in another, convert the band (mechanical) and then convert the cup by counting steps, not by matching letters.
Example: you wear a UK 32F. UK F is the 7th cup step (A, B, C, D, DD, E, F). Seventh step in US is G (or DDD in some brands), in EU it is G. Band 32 = EU 70 = FR 85. So order a US 32G/32DDD, an EU 70G, or an FR 85G.
Reverse example: you wear a US 36DD from Victoria’s Secret. DD is the 5th step. Band 36 = EU 80 = FR 95. In UK that is 36DD (same letter here), in EU 80E. But because VS bands run loose, you may find a UK 34E or EU 75F fits better; that is the sister size with the firmer band.
For the wider clothing picture, the women’s clothing converter handles dress, top and bottom sizes across the same regions.
FAQ
Is a US DD the same as a UK DD?
Yes, for that one size. Both are the fifth cup step (10–12.5 cm difference). They diverge from the next size on: the sixth step is US DDD or E, but UK E; the seventh is US G or F, but UK F.
What is a 34D in European sizing?
EU 75D. The band converts as 34 inches to 75 centimeters and D is the fourth cup step in both systems. In French sizing it is 90D; in Italian, 3D; in Australian, 12D.
Why does my band size feel different in every brand?
Three reasons: some brands still use the +4 inch method, so their 34 fits like a 30 measured; some brands round to different intervals; and fabric and elastic differ. Measure the band of a bra that fits, stretched to its usual wearing tension, and compare it to the flat band length listed by the new brand. Most UK and EU brands publish that figure.