🩱 Bra Size Converter
A US 34DD is a UK 34DD but an EU 75E and a FR 90E, band systems translate cleanly, cup letters diverge past D. Convert below, everything happens on your device.
US
34D
UK
34D
EU / DE
75D
FR / ES
90D
AU (band)
12D
Sister sizes (same cup volume):
Your measurements never leave this page, nothing is transmitted or stored.
How to measure
- Band: measure snugly around the ribcage, directly under the bust, in inches or cm, exhale first; the tape should be level and firm.
- Bust: measure around the fullest point, unpadded, tape parallel to the floor.
- Cup = bust minus band: each inch (2.5 cm) of difference is one cup step (1" ≈ A, 2" ≈ B, 3" ≈ C…).
- Enter your current size in the converter to see every system plus your sister sizes.
Sister sizes share the same cup volume on a different band: 34DD, 36D and 32DDD hold the same, the letter changes because cup letters are relative to the band. If a band rides up, go down a band and up a cup; if it digs in, the reverse. Roughly 8 in 10 people measure into a different size than they habitually buy, which is why the sister-size feature exists.
Band size conversion chart
| US / UK | EU / DE | FR / ES | IT | AU |
|---|---|---|---|---|
| 28 | 60 | 75 | 0 | 6 |
| 30 | 65 | 80 | 1 | 8 |
| 32 | 70 | 85 | 2 | 10 |
| 34 | 75 | 90 | 3 | 12 |
| 36 | 80 | 95 | 4 | 14 |
| 38 | 85 | 100 | 5 | 16 |
| 40 | 90 | 105 | 6 | 18 |
| 42 | 95 | 110 | 7 | 20 |
| 44 | 100 | 115 | 8 | 22 |
Cup ladder comparison
| Cup step | US | UK | EU |
|---|---|---|---|
| 1 | A | A | A |
| 2 | B | B | B |
| 3 | C | C | C |
| 4 | D | D | D |
| 5 | DD | DD | E |
| 6 | DDD | E | F |
| 7 | G | F | G |
| 8 | H | FF | H |
| 9 | I | G | I |
| 10 | J | GG | J |
Frequently asked questions
What is a sister size?
The same cup volume on a different band length. One band size down + one cup letter up (or the reverse) keeps volume constant: 34DD ↔ 32DDD ↔ 36D. Useful when a style fits in the cup but not the band.
What is a US 34DD in EU sizing?
75E. The band converts 34→75 (inches to the EU cm scale), and the fifth cup is DD in the US ladder but E in the EU ladder.
Why do UK and US cups differ above D?
The ladders fork: US goes D, DD, DDD, G…; UK goes D, DD, E, F, FF, G…. A UK F is roughly a US DDD/G, always convert by counting cup steps, not matching letters.
Is my measurement data stored anywhere?
No. Like every LazyTools tool, the converter runs entirely in your browser, body measurements are never transmitted, logged or stored. You can verify with your browser’s network tab.
Is this bra size converter private?
Yes. It runs entirely in your browser. Sizes and body measurements are never sent to a server, logged or stored, and the page works offline.