Bra Size Converter

International Bra Size Converter for Australia, the UK, US, EU and France

Bra sizes are written differently around the world, which makes shopping online from overseas brands confusing. This international bra size converter turns an Australian, New Zealand, UK, US, EU or French size into all of the others at once. Choose the system on your label, then your band and cup, and the headline shows the match in every system. You will also see sister sizes and a full chart, and you can estimate a starting size from your measurements.

Whether you call it a bra converter or a bra size conversion chart, the idea is the same: every size is a band number plus a cup letter, and each country counts those two things differently.

How Bra Size Conversion Works

Worked Example: AU 12C

An Australian size 12C converts to: AU 12C = US 34C = UK 34C = EU 75C = FR 90C. The AU band 12 plus 22 is a 34 band in the UK and US, which is EU 75 and FR 90, and the C cup is the third cup step in every system. Its sister sizes are AU 10D and AU 14B.

To estimate a size from measurements, take an underbust of 76 cm (29.9″) and a bust of 92 cm (36.2″). The underbust rounds to an even band of 30, and the bust is 6″ larger, which gives about UK 30E, or AU 8E. That is an estimate only, so a professional fitting is best.

Common Bra Size Conversions

Why Sizes Differ Between Brands

A size chart is a guide, not a guarantee. Brands cut bands and cups differently, fabrics stretch differently, and styles such as underwire, wire-free, sports and balconette bras sit differently on the same body. Some brands use their own cup lettering beyond DD, which is why US and UK letters can disagree. Treat a converted size as the place to start, try the next size up or down in each direction, and compare the brand's own chart when it is available.

Bodies and bra needs also change over time, so a size that worked years ago may not suit you now. If you are unsure, a fitting at a department store or lingerie shop is a quick way to check your starting size.

Frequently Asked Questions

How does an international bra size converter work?

Every system describes the same two things, a band and a cup, using different numbers and letters. A converter finds your band and cup step and reads off the matching label in each system. For example, AU 12C = US 34C = UK 34C = EU 75C = FR 90C.

How do I convert a bra size from UK to US?

For most sizes the UK and US are the same: the band numbers match, and the cups match up to D. UK 34C is US 34C, and UK 34D is US 34D. The difference starts at DD: UK 34DD is US 34DD/E, UK 34E is US 34DDD/F and UK 34F is US 34G. US letters beyond DD vary by brand, so check the brand's own chart.

How do I convert an Australian bra size to US?

Add 22 to the Australian band to get the US band, and then convert the cup. AU 12D is US 34D, and AU 14C is US 36C. Past D the cups differ, so AU 16DD is US 38DD/E. Most Australian brands use UK-style cups, but some do not, so use this as a guide.

What is the bra size conversion from the US to the UK?

The band stays the same and only larger cups change name. US 34DD/E is UK 34DD, and US 34DDD/F is UK 34E. US 34G is UK 34F and US 34H is UK 34FF. Some US brands label the same cup differently after DD.

What are bra sizes in Australia compared with the USA?

Australian bands are numbered 6, 8, 10 and so on, while US bands are in inches (28, 30, 32 and so on). The AU band is the US band minus 22, so AU 10 is US 32, AU 12 is US 34 and AU 14 is US 36. Your size in the table above shows the full AU-to-US match, cup included.

How do I convert a bra size from Australia to the UK?

Add 22 to the Australian band and keep the cup letters. AU 12C is UK 34C, AU 14D is UK 36D and AU 10B is UK 32B. Most Australian brands follow UK cup sequencing (including DD, E, F, FF), though brands vary.

What are sister sizes?

Sister sizes have a similar cup volume on a different band. Go one band down and one cup up, or one band up and one cup down. The sister sizes of AU 12C are AU 10D and AU 14B. They can help if your usual size is out of stock or the band feels too tight or loose, but the fit will not be identical.

How do I find my bra size from measurements?

Measure snugly around your ribcage under the bust (underbust) and around the fullest part of your bust. Round the underbust in inches to the nearest even number for the band, then use the difference in inches between your bust and the band for the cup: 1 inch is A, 2 is B, 3 is C and so on. An underbust of 76 cm and a bust of 92 cm gives about UK 30E, or AU 8E. This is an estimate only, so a professional fitting is best.

Are EU and French bra sizes different?

Yes. The EU band is in centimetres in steps of 5 (60, 65, 70 and so on), and the French, Spanish and Belgian band is the EU band plus 15. UK/US 34 is EU 75 and FR 90. The cup letters are the same in both systems, so AU 12C is EU 75C and FR 90C.