Bra Atlas fitting card
34BUK · same in the US
Measures about 34 in underbust and 36 in bust. Same cups as 32C and 36A.
- UK
- 34B
- US
- 34B
- EU
- 75B
- FR
- 90B
- AU
- 12B
- JP
- C75
Same cups 32C·34B·36A
34B sister size chart, conversions and measurements
34B reads the same on the Victoria's Secret and Wacoal international charts, but M&S's US column prints it as 34A. Its nearest sisters are 32C and 36A.
Every sister of 34B
- 30DTighter band by 4 in, 2 cup letters up (US 30D, EU 65D)
- 32CTighter band by 2 in, 1 cup letter up (US 32C, EU 70C)
- 34BThis size (US 34B, EU 75B)
- 36ALooser band by 2 in, 1 cup letter down (US 36A, EU 80A)
- 38AALooser band by 4 in, 2 cup letters down (US 38AA, EU 85AA)
32C
tighter band
34B
your size
36A
looser band
Same cups, three bands: 32C, 34B, 36A hold the same cup volume.
Tape measurements that give 34B
Computed by the Bra Atlas engine with the measured-band method, and checked by running each pair back through it.
| Snug underbust | Fullest bust | Result |
|---|---|---|
| 33 in (84 cm) | 35.5 in (90 cm) | 34B |
| 33.5 in (85 cm) | 35.75 in (91 cm) | 34B |
| 34 in (86 cm) | 36 in (91 cm) | 34B |
| 34.5 in (88 cm) | 36.25 in (92 cm) | 34B |
Our +4 comparison gives 38AA for 34 in underbust and 36 in bust. With an odd 33 in underbust and a 35 in bust we print 34A/B; our fixture-backed model of calculator.net's unpadded row gives 34B. How the +4 and measured-band methods work.
What is particular about 34B
What our +4 comparison returns
A 34 in underbust and a 36 in bust measure 34B on the measured-band method. Our +4 comparison pads the band to 38 in, leaving 36 − 38 = −2 in. Using AA for a difference below 1 in gives 38AA. It has the same sister-size volume index as 34B, but its band is 4 in longer.
A small step either way
If a 34B band rides up, 32C is one band tighter with the same cups. If it digs in, 36A is one band looser. Both keep the cup volume of 34B.
The same in the UK and US
On the Victoria's Secret and Wacoal international charts, UK 34B is US 34B. Our conversion model also keeps 32C, 36A and 38AA unchanged. M&S's US column differs: UK 34B becomes US 34A, 36A becomes 36AA and 38AA becomes 38AAA. Check the UK row when using that M&S table.
34B in every system
| UK | US | EU | FR | AU | JP (approx.) |
|---|---|---|---|---|---|
| 30D | 30D | 65D | 80D | 8D | E65 |
| 32C | 32C | 70C | 85C | 10C | D70 |
| 34B | 34B | 75B | 90B | 12B | C75 |
| 36A | 36A | 80A | 95A | 14A | B80 |
| 38AA | 38AA | 85AA | 100AA | 16AA | A85 |
Other sizes and tools
- Bra size calculatorCheck that 34B is still your size, with both methods shown
- Sister size chartThe full diagonal chart and fit fixes
- Fit checkTick what feels wrong in your 34B; get the size to try next
- Brand size chartsHow Victoria's Secret, ThirdLove, Wacoal, SKIMS, M&S and Freya size charts differ
- B cup, explainedWhat the B cup means, and why it changes by band
- 34CSame 34 band, 1 cup letter up
- 32BSame cup letter on a 32 band
- 34DSame 34 band, 2 cup letters up
- 34DDSame 34 band, 3 cup letters up
Sources
Each source was opened and checked on the date shown, or on 25 September 2026. Where sources disagree, the page says so instead of picking one silently.
- Wikipedia, "Bra size": UK and US cup ladders, the +4 method, EN 13402 and JIS cup steps
- White J, Scurr J. Evaluation of professional bra fitting criteria for bra selection and fitting in the UK. Ergonomics 2012;55(6):704-711: 45 women; the traditional method overestimated band and underestimated cup
- Victoria's Secret Customer Care, "Size & Fit: International Size Chart (Outside the U.S.)": US sizes sold; bands 30 to 44, cups AA to DDD; US DDD = UK E (opened 25 September 2026)
- Wacoal, "International Size Guide": UK AA to GG paired with US AA to J; AUS/NZ keeps FF and GG; band and cup rows are separate, not a stock list (opened 13 October 2026)
- Marks & Spencer US, "Bras size guide": UK, AU/NZ, US/CA, EU and FR conversion table (opened 25 September 2026)