Bra size conversion chart
A bra size is a band number plus a cup letter. Bands convert in even steps of about 2.5 cm; cups are trickier because the same letter means different volumes on different bands — always convert band and cup together.
| Underbust (cm) | US / UK band | EU band | FR band | AU band |
|---|---|---|---|---|
| 63–67 | 30 | 65 | 80 | 8 |
| 68–72 | 32 | 70 | 85 | 10 |
| 73–77 | 34 | 75 | 90 | 12 |
| 78–82 | 36 | 80 | 95 | 14 |
| 83–87 | 38 | 85 | 100 | 16 |
| 88–92 | 40 | 90 | 105 | 18 |
| 93–97 | 42 | 95 | 110 | 20 |
Notes
- Cup letters match between US and UK up to D; above D the UK continues DD, E, FF while the US uses DD then DDD/G.
- FR band sizes are EU + 15; FR cups are offset by one letter (FR E = US D).
- Measure the underbust snugly on exhale; if between bands, the smaller band usually fits after washing.
Frequently asked questions
- Is US 34C the same as EU 75C?
- Yes — a US 34 band equals EU 75, and the C cup is the same volume on that band in both systems.
- Why does my cup size change when the band changes?
- Cup volume is relative to the band: 34C and 36B hold nearly the same volume, a concept called sister sizing.
- How do I measure for a bra?
- Measure the underbust snug on an exhale for the band, and the bust at the fullest point; the inch difference indicates the cup (1 in ≈ one letter).