International Bra Size Converter: US, UK, EU, AU Chart & Guide

Table of Contents

 

Introduction

Using an international bra size converter sounds simple — until you order a 34C from a UK brand and it shows up feeling nothing like your usual size. That happens a lot. Professional bra fitting studies show nearly 80% of women wear the wrong bra size, often because of incorrect band measurement. Add international shopping into the mix and it gets worse.

Band sizes, cup progressions, and brand grading all vary by country. A bra size chart international reference isn't just useful — it's necessary. This guide covers US, UK, EU, AU, and more, with a step-by-step measuring guide and practical tips for shopping across borders.

 

Why Do Bra Sizes Differ Around the World?

Different countries don't agree on how to measure or label bra sizes. The US and UK measure bands in inches; the EU uses centimeters; Australia uses a clothing-style numeric system. There's no international standard — manufacturers developed their own systems over decades.

The two biggest pain points:

•       Cup letters branch after D. US: D, DD, DDD. UK: D, DD, E, F. A US DD = UK E — not UK DD.

•       Band units don't convert directly. US 34 (inches) = EU 75 (cm). Same body, completely different numbers.

The University of Portsmouth's Research Group in Breast Health found inconsistent bra fit is one of the leading causes of breast discomfort among women globally — most traced back to band and cup measurement errors.

 

International Bra Size Conversion Chart

Your master bra size conversion chart — US, UK, EU, and AU in one place.

 

Band Size Conversion

US Band	UK Band	EU Band	AU Band
28	28	60	6
30	30	65	8
32	32	70	10
34	34	75	12
36	36	80	14
38	38	85	16
40	40	90	18
42	42	95	20

 

Cup Size Conversion

US Cup	UK Cup	EU Cup	AU Cup
A	A	A	A
B	B	B	B
C	C	C	C
D	D	D	D
DD	DD	E	DD
DDD/F	E	F	E
G	F	G	F

 

Bra Size Comparison Chart: Common Sizes

US	UK	EU	AU
32B	32B	70B	10B
34B	34B	75B	12B
34C	34C	75C	12C
34D	34D	75D	12D
36D	36D	80D	14D
38DD	38DD	85E	16DD

 

 

 

Bra Size Comparison Chart by Country (Japan, Korea, China, France & Italy)

Shopping Asian or European brands? Band and cup labeling shifts again. Here's how common US sizes translate.

 

US	UK	EU	AU	Japan	Korea	China	France	Italy
32B	32B	70B	10B	70B	70B	70B	85B	0B
34B	34B	75B	12B	75B	75B	75B	90B	1B
34C	34C	75C	12C	75C	75C	75C	90C	1C
36D	36D	80D	14D	80D	80D	80D	95D	2D

 

•       Japan and Korea use EU-style band numbers (cm) but US-style cup letters.

•       32/70 bra size China follows EU bands — 70B China = 32B US.

•       French sizing adds ~15 to the EU band: EU 75 = French 90.

•       Italian sizing uses a numeric scale: 0, 1, 2, 3 (EU 70, 75, 80, 85).

 

US to UK Bra Size Converter: Quick Chart

US and UK bands share the same number — but cup letters split above DD. This trips up most US shoppers buying UK brands.

 

US Size	UK Equivalent
34C	34C
34D	34D
34DD	34DD
34DDD / 34F	34E
34G	34F
36DDD	36E

 

UK brands often carry cups up to K — great if you've struggled to find your size. For fit help after converting: Confused About Bra Straps & Gaps?

 

US to EU Bra Size Converter

: Step-by-Step

EU bands are in centimeters. US 34 = EU 75. Formula: US band × 2.54, rounded to the nearest 5.

 

US Band	EU Band
30	65
32	70
34	75
36	80
38	85

 

Cups A–D are identical across US and EU. Above D: EU E = US DD, EU F = US DDD.

 

US to AU Bra Size Converter

Australian bra sizing uses a numeric back system — AU 12 = US 34. Cups follow UK convention.

 

US Size	AU Equivalent
32B	10B
34B	12B
34C	12C
36D	14D
38DD	16DD

 

US 34DDD = AU 12E (not 12DDD). Always check the cup column above D.

 

How to Measure Your Bra Size at Home

Two measurements, a soft tape measure, two minutes. Most errors come from measuring over an old bra or pulling the tape uneven.

Step 1 — Band (underbust): Wrap the tape snugly under your bust, level all the way around. Round to the nearest even number. Example: 33" → band size 34.

Step 2 — Bust: Measure around the fullest part, tape parallel to the floor. Don't pull tight.

Step 3 — Cup: Subtract band from bust.

 

Difference	Cup
1 inch	A
2 inches	B
3 inches	C
4 inches	D
5 inches	DD
6 inches	DDD

 

 

Once you know your size, front-closure styles are especially forgiving. The Magic Front Closure Seamless Push-Up Bra lets you adjust from the front so you can see the fit. The Magic Posture Bra adds back support if that's a priority.

Quick reference: Magic Bra's international size conversion table

 

Why Bra Sizes Change Over Time

Your bra size isn't permanent. The main reasons it shifts:

•       Weight changes — breast tissue is largely fat; a 10–15 lb change can move you a cup or band size.

•       Pregnancy and nursing — many women go through 2–3 sizes across a pregnancy. Measure each trimester.

•       Hormonal changes — density shifts during the menstrual cycle, perimenopause, and menopause. Measure mid-cycle, first thing in the morning.

•       Aging — breast tissue loses density over time, which can change the cup shape you need even if volume stays similar.

Remeasure every 6–12 months, or anytime your clothes are fitting differently.

 

Sister Sizes, Calculators & Return Tips

Sister Sizes

Sister sizes share the same cup volume with a different band — useful when your exact size is sold out or the band doesn't feel right.

 

If You Wear	Go Down a Band	Go Up a Band
34B	32C	36A
34C	32D	36B
36D	34DD	38C

 

Band too loose? Go down a band, up a cup. Band too tight? Go up a band, down a cup.

Using a Bra Size Converter Calculator

A bra size converter calculator takes your underbust and bust in inches and outputs your size with international equivalents. Measure braless, use fresh measurements, and cross-check against the charts above. Working from EU cm? Divide by 2.54 to get inches first.

Return Policies

Before ordering internationally: confirm whether the brand covers return shipping (most don't), look for store credit exchanges, and check fit guarantees. Reviews from women with similar measurements are more reliable than brand size charts alone.

 

Common Sizing Mistakes

•       Odd band sizes. Bands come in even numbers — 33" rounds to 34.

•       Skipping the cup column in EU conversions. EU E = US DD. Most people get the band right but miss this.

•       Using old measurements. Remeasure after any body change.

•       Too-tight band for "more support." A snug band causes back bulge. Slide two fingers underneath to check.

•       Assuming brand consistency. A 34C from one brand can fit like a 34D from another. Try a sister size before returning.

 

Conclusion

An international bra size converter only works well when your starting measurements are accurate. With those in hand, this bra size chart international guide covers US, UK, EU, AU, and Asian and European sizing. Core rules: US and UK bands match in number but cups diverge above DD; EU bands are in centimeters (US 34 = EU 75); AU uses numeric back sizing; Asian and French brands follow EU band conventions. Measure regularly, use sister sizes when needed, and check return policies before any international order.

Bookmark Magic Bra's international size conversion table for a quick reference anytime.

 

Key Takeaways

Q: What's the fastest way to convert US to EU?

Multiply your US band by 2.54 and round to the nearest 5. Cups A–D stay the same; US DD = EU E; US DDD = EU F.

Q: Why does my UK size feel different with the same band number?

Cups split after D. US DDD = UK E, not UK DDD. Always check the cup column.

Q: Is 34B the same everywhere?

Cup B is consistent globally. The band changes: US/UK = 34, EU = 75, AU = 12.

Q: Does Chinese sizing follow EU?

Yes. A 32/70 bra size in China = US 32B.

How do I convert AU bra sizes to US for international shopping?

Australian back sizes (8, 10, 12, 14, 16) correspond to US bands of 28, 30, 32, 34, 36. AU 12C = US 34C. For cups above D, AU follows UK convention: AU E = US DDD.

University of Portsmouth Research Group in Breast Health — bra fit research

American Chiropractic Association — posture and supportive undergarments

Professional bra fitting industry research — fitting statistics