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Your size in UK
34B
All conversions for this size
How to measure your bra size
01
Band size — underbust
Measure snugly around your ribcage directly under your bust. Round to the nearest even number. US/UK: if odd, add 1 inch.
02
Bust measurement
Measure loosely around the fullest part of your bust, keeping the tape parallel to the floor. Note this number.
03
Calculate your cup
Subtract your band from your bust. Each inch = one cup size: 1"=A, 2"=B, 3"=C, 4"=D, 5"=DD/E, 6"=DDD/F. Varies slightly by brand.
04
Try sister sizes
If it doesn't feel right, try a sister size — go up one band and down one cup (34C→36B) or vice versa. Same cup volume, different fit.
International band size chart
How US/UK band numbers map across all 7 sizing systems.
| 🇺🇸 US / 🇬🇧 UK | 🇦🇺 AU | 🇪🇺 EU | 🇫🇷 France | 🇮🇹 Italy | 🇯🇵 Japan |
|---|
🇺🇸 US cups
ABCDDDDDDDDDD
🇬🇧 UK / 🇦🇺 AU cups
ABCDDDEFFF
🇪🇺 EU / 🇫🇷 FR / 🇮🇹 IT / 🇯🇵 JP cups
ABCDEFGH
Bra size questions
Why do bra sizes differ between countries?
Sizing systems evolved independently using different conventions. US and UK look identical (e.g. 34B) but cups diverge at larger sizes. EU uses centimeters. France and Italy add a fixed offset to the EU band. Japan lists the cup letter first.
Is US sizing the same as UK?
Band numbers are the same (32, 34, 36…) but cups differ at larger sizes. US uses DD, DDD, DDDD while UK uses DD, E, F, FF, G. For cups A through D they are identical. A US 34DD = UK 34E.
How do I convert to EU sizing?
EU bands are in centimeters. A US/UK 32 ≈ EU 70, 34 ≈ EU 75, 36 ≈ EU 80, 38 ≈ EU 85, 40 ≈ EU 90. EU cups use the same letters as UK through E, then continue F, G, H where US would use DDD, DDDD.
What is a French bra size?
French sizing adds 15 to the EU band number. So EU 75B = French 90B. Italian sizing traditionally adds 20 (EU 75B = Italian 95B). Cup letters are the same as EU.
How does Japanese sizing work?
Japanese sizing lists the cup letter first, then the band in centimeters (e.g. B75 = US 34B). Japanese sizing runs slightly smaller — if between sizes, size up. Major brands like Wacoal and Triumph often include both JP and EU sizing on labels.
Why might the converted size not fit perfectly?
Conversion tables give the mathematical equivalent, but fit varies by brand, fabric, and cut. Use this as your starting point and try sister sizes if needed — one band up + one cup down, or vice versa.