AU bra size calculator
Australian Bra Size Calculator
Calculate your Australian (AU/NZ) bra size from your underbust and bust measurements, in inches or centimetres.
How Australian bra sizing works
Australian bra sizing uses a different band label from US sizing. In this verified Wearavo dataset, the AU band is 22 less than the US band, so a US 34 band maps to AU 12 and a US 36 band maps to AU 14.
The cup label still matters. AU cup letters follow the UK/AU alphabet: A, B, C, D, DD, E, F, and onward. That means an AU label can look different from a US label even when the intended fit is similar.
Use the calculator as the starting point, then check the real fit: the band should stay level, cups should sit smoothly, and the center gore should lie close on wired bras. Brand charts can still vary, especially in fuller cup steps.
Last updated: July 9, 2026
Australia and New Zealand use the same sizes
AU and NZ bra sizes are normally treated as the same system. A result like AU 12D can be read as an NZ 12D when a New Zealand retailer uses AU/NZ sizing.
That does not mean every brand fits identically. Use the shared AU/NZ label to get into the right area, then compare the retailer's size chart, fabric, cup depth, and return policy before buying.
AU to US / UK / EU quick reference
These common examples come from the same verified size table used by the calculator. Use them for orientation, then open a size hub for the full conversion and sister-size details.
Sister sizes in Australian sizing
Sister sizes are useful when the cup volume feels close but the band does not. In AU terms, moving to a snugger band usually means a lower AU number and a larger cup step; moving looser means a higher AU number and a smaller cup step.
This is especially helpful for AU/NZ shoppers because the band number looks different from US sizing. Use the sister-size finder instead of guessing across labels.
Find AU sister sizesMeasuring in centimetres
Use a soft tape and keep it level. Measure under the bust for the band starting point, then around the fullest part of the bust for the cup step. Enter both numbers in centimetres with the cm toggle selected.
If you only have inch measurements, switch the toggle to inches. The result still uses AU/NZ as the output system when AU is selected.
FAQ
What is my Australian bra size?
Enter your underbust and bust measurements, choose cm or inches, and keep AU selected as the result country. The calculator gives an AU/NZ starting size plus equivalent labels in the other supported systems.
How do I convert a US bra size to Australian?
For the band, Australian sizing is commonly 22 less than the US band, so a US 34 band maps to AU 12. Cup labels should still be checked in the full conversion row because fuller cups can differ by system.
Do Australia and New Zealand use the same bra sizes?
Yes. Australia and New Zealand generally use the same AU/NZ bra sizing system, although individual brand charts can still vary.
How do I measure my bra size in centimetres?
Measure snugly around the ribcage under the bust, then measure around the fullest part of the bust. Enter both measurements in cm and use the result as a starting point for a fit check.
What is the sister size of my Australian bra size?
A sister size changes the band and cup in opposite directions to keep cup volume close. Use the sister-size finder after you know your AU/NZ starting size.