Bra Size Conversion Hub
Convert AU sizes to UK, US and EU - and understand which half of the conversion you can trust.
An Australian band is the UK or US number minus 22. AU 10 is UK 32 and US 32. EU bands run on a different scale entirely – AU 10 is EU 70. Cup letters match the UK exactly, usually match the EU up to D, and diverge from the US from DD upwards.
Pick a conversion
AU to UK
Same cup letters, band plus 22. The most reliable of the four.
Open →
AU to US
Same band arithmetic, different cup names above D.
Open →
AU to EU
Centimetre-based bands, letters that mostly follow the UK.
Open →
US to AU
Coming the other way, from an American label.
Open →
UK to AU
Coming the other way, from a British label.
Open →
Full AU chart
Underbust and bust difference to AU size, from scratch.
Open →
Band conversion is the easy half
AU/NZ, UK and US bands describe the same underbust measurements on different numbering. AU 8 is UK 30 and US 30, and every AU step of two adds two to the UK or US number. EU bands are a separate, centimetre-derived scale.
Scroll the table sideways on a narrow screen.
| Snug underbust | AU / NZ band | UK band | US band | EU band |
|---|---|---|---|---|
| 63–67 cm | 8 | 30 | 30 | 65 |
| 68–72 cm | 10 | 32 | 32 | 70 |
| 73–77 cm | 12 | 34 | 34 | 75 |
| 78–82 cm | 14 | 36 | 36 | 80 |
| 83–87 cm | 16 | 38 | 38 | 85 |
| 88–92 cm | 18 | 40 | 40 | 90 |
| 93–97 cm | 20 | 42 | 42 | 95 |
| 98–102 cm | 22 | 44 | 44 | 100 |
| 103–107 cm | 24 | 46 | 46 | 105 |
| 108–112 cm | 26 | 48 | 48 | 110 |
| 113–117 cm | 28 | 50 | 50 | 115 |
| 118–122 cm | 30 | 52 | 52 | 120 |
| 123–127 cm | 32 | 54 | 54 | 125 |
Cup naming is the hard half
Australian and British cups run A, B, C, D, DD, E, F, FF, G, GG, H. American cups historically run A, B, C, D, DD, DDD and then diverge by brand, which is why an AU F is commonly a US G but is sometimes labelled DDDD. European sizing generally continues the alphabet without doubling – an AU DD is an EU E.
Scroll the table sideways on a narrow screen.
| AU / UK cup | Common US label | Common EU label | Display note |
|---|---|---|---|
| A | A | A | Usually aligned |
| B | B | B | Usually aligned |
| C | C | C | Usually aligned |
| D | D | D | Usually aligned |
| DD | DD/E | E | US naming varies |
| E | DDD/F | F | US naming varies |
| F | G | G | Verify brand chart |
| FF | H | H | Verify brand chart |
| G | I | I | Verify brand chart |
| GG | J | J | Verify brand chart |
| H | K | K | Verify brand chart |
| HH | L | L | Verify brand chart |
| J | M | M | Verify brand chart |
| JJ | N | N | Verify brand chart |
| K | O | O | Verify brand chart |
What this page does not claim
These are conventions, not guarantees, and they are the conventions this site uses – stated so you can check them. No conversion table overrides the chart published by the brand you are actually buying. Read the calculation methodology for how the tables were built and when they were last reviewed.