Australian Bra Size Chart
Underbust to AU band, bust difference to cup, and the equivalent UK, US and EU labels.
Australian bra sizes use an even-numbered band (8, 10, 12 and up) with a letter cup. The band comes from your snug underbust measurement. The cup comes from the difference between your full bust and the middle of that band range – roughly 2 cm of difference per cup step. An AU band is always the UK or US number minus 22: AU 12 is UK 34 and US 34.
Underbust to band size
Measure snugly directly under the bust, level all the way round, while breathing normally. Find your measurement in the first column.
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 |
If your measurement lands exactly on a boundary – 67.5 cm, say – try both bands. The band is the part of a bra that does most of the supporting, so a band that feels firm but not painful on the loosest hook is doing its job.
Difference to cup size
Take your full bust measurement, subtract the midpoint of your band range, and read the cup from the difference. Using the midpoint rather than your raw underbust is what keeps the chart consistent: two people with the same band should get the same cup for the same bust.
Scroll the table sideways on a narrow screen.
| Difference | AU / UK cup |
|---|---|
| 10 – under 12 cm | A |
| 12 – under 14 cm | B |
| 14 – under 16 cm | C |
| 16 – under 18 cm | D |
| 18 – under 20 cm | DD |
| 20 – under 22 cm | E |
| 22 – under 24 cm | F |
| 24 – under 26 cm | FF |
| 26 – under 28 cm | G |
| 28 – under 30 cm | GG |
| 30 – under 32 cm | H |
| 32 – under 34 cm | HH |
| 34 – under 36 cm | J |
| 36 – under 38 cm | JJ |
| 38 – under 40 cm | K |
Australian cup letters follow the UK sequence, which doubles letters rather than adding a third D: A, B, C, D, DD, E, F, FF, G, GG and so on. That is why an Australian F is not the same letter as an American F.
How AU sizes are written elsewhere
Band conversion is arithmetic and reliable. Cup naming is a convention, and it is the part that diverges – badly, at larger cups.
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 |
Read the conversion hub for the two-way charts, and always check the retailer’s own chart before ordering from overseas.
A worked example
Someone measures 74 cm underbust and 90 cm full bust.
- 74 cm falls in the 73–77 cm range, so the band is AU 12.
- The midpoint of 73–77 is 75. 90 − 75 = 15 cm.
- 15 cm sits in the 14 to under 16 cm row, so the cup is C.
- The starting size is AU 12C, written UK 34C, US 34C and EU 75C.
Their sister sizes are 10D and 14B – same approximate cup volume, different band. See sister sizes.
Common mistakes when reading a chart
- Adding inches to the underbust. Some older charts tell you to add 10 or 12 to your underbust before choosing a band. That habit comes from stiffer mid-century fabrics and usually produces a band several sizes too loose today.
- Measuring over a padded bra. Padding adds to the full bust and inflates the cup. Measure over a thin, unpadded bra or bare skin.
- Assuming the letter travels. An AU DD is an EU E. An AU F is usually a US G. The letter is a label, not a measurement.
- Treating the chart as final. Two bras of the same nominal size from different brands can differ by a full cup. The chart gives you the size to try first.
Why brand charts disagree with this one
There is no legal standard for bra sizing in Australia or anywhere else. Every brand builds its own size set around a fit model, then publishes a chart that describes that set. A brand whose fit model has a shallower breast shape will grade its cups differently to one whose model is fuller, even at identical nominal sizes. This chart describes a widely used Australian convention and is the basis of our calculator – it is a well-documented starting point, not an authority that overrides the brand you are actually buying.