knowhersize

Australian Bra Size Calculator

Measure snugly under your bust and loosely around the fullest part in centimetres. The calculator gives your Australian bra size, such as 10C, 12D or 14DD, with sister sizes and the US, UK and EU equivalents. New Zealand uses the same sizes.

Reviewed · How we work

  1. Method
  2. Details
  3. Size

What have you got to go on?

Show in
Also fits — firmer band— looser band
Printed on tag

Where is the size on a tag?

On the back band near the hooks, or on the side seam. Many tags list several countries in a row: pick the line for the country where it was bought. No tag? Try another bra she wears often, or switch to Her clothes.

Does that bra fit her well?
Her clothes size
Her usual top size
Her bust, for her frame

Clothes sizes measure her whole body, not her bust, so this gives a range. Good enough for bralettes and sleepwear.

Which frame is closest to hers?
Her bust, for her frame
Measure snug, tape level

Under the bust, snug

Around the fullest part, loose

Confidence
High

A beige bra on a sunlit rattan chair with eucalyptus

How to measure for an Australian bra size

You need a soft tape measure and about a minute. Measure over a thin, unpadded bra or none at all.

  1. Underbust (band). Wrap the tape snug and level just under your bust, and breathe out. This sets your band. For example, 76 cm (about 30 in) is an AU 8, 81 cm (32 in) an AU 10 and 86 cm (34 in) an AU 12.
  2. Bust (cup). Measure loosely around the fullest part, keeping the tape level. If you’re fuller at the bottom, also measure leaning forward; the calculator uses the larger number.
  3. Read your size. Each 2.5 cm (one inch) of difference between bust and band is one cup. The big number is your AU size; the line below it shows your sister sizes.

Australian sizes next to US and UK

Australian bands are the inch band minus 22. Cup letters follow the UK, so they match US letters up to DD and then split.

AUUKUSEU
10B32B32B70B
12C34C34C75C
12DD34DD34DD75E
14D36D36D80D
14E36E36DDD80F
16F38F38G85G

For the full chart and every band, see the Australian bra size conversion.

Common surprises

  • The band is smaller than expected. Many women wear a band that’s too loose. The band does most of the support, so it should feel firm on the loosest hook.
  • The cup letter is bigger than expected. When the band drops, the cup letter rises to hold the same volume. An AU 14B and an AU 10D are related sizes in this way; the letter on its own says little.
  • Brands differ. Expect about one size of difference between labels. Treat your result as the size to try first.

Buying a gift for someone in Australia or New Zealand? Use Her bra tag with the tag set to AU, then save the size to her size card.

Sources & method: sizing rules follow the standard band-and-cup system used by UK, US, AU and EU brands, checked against fitting guides from specialist retailers and fitting communities. How we work.

Questions

How do Australian bra sizes work?

The band is a dress-style number (8, 10, 12, 14 and so on) and the cup is a letter. AU bands are the UK or US inch band minus 22, so a 34 band is an AU 12. Cup letters follow the UK: A, B, C, D, DD, E, F, FF, G.

What is AU 12C in US sizes?

A US 34C. It's also a UK 34C and an EU 75C.

Is my bra band the same as my dress size?

Not necessarily. The numbers look alike, but the band comes from your underbust measurement, not your dress size. Plenty of women who wear a size 12 dress wear a 10 or 14 band.

Are New Zealand bra sizes the same as Australian?

Yes. New Zealand brands and shops use the same band numbers and cup letters as Australia.

Should I measure in centimetres or inches?

Centimetres are fine; the calculator converts. Measure to the nearest centimetre with the tape level all the way round.

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