US Size 40B in AU — Women's Bras
US 40B =
AU 18B
United States (US) women's bras size 40B converts to Australian (AU) size 18B. This is a standard conversion used across most major bras brands and retailers.
When shopping from Australian brands like Berlei, Bonds, Bras N Things, look for size 18B on the label. Keep in mind that sizing can vary slightly between brands, so always check the specific brand's size chart if available.
For reference, one size down (US 40A) is AU 18A, and one size up (US 40C) is AU 18C. If you're between sizes, most fitting guides recommend sizing up for comfort.
This conversion is especially useful for international shoppers purchasing women's from Australian retailers or ordering United States-sized products from brands like Victoria's Secret or ThirdLove to ship internationally.
Quick Converter
US 40B =
AU 18B
Full US to AU Women's Bras Size Chart
| US | AU |
|---|---|
| 30A | 8A |
| 30B | 8B |
| 30C | 8C |
| 30D | 8D |
| 30DD | 8DD |
| 32A | 10A |
| 32B | 10B |
| 32C | 10C |
| 32D | 10D |
| 32DD | 10DD |
| 32DDD | 10E |
| 34A | 12A |
| 34B | 12B |
| 34C | 12C |
| 34D | 12D |
| 34DD | 12DD |
| 34DDD | 12E |
| 36A | 14A |
| 36B | 14B |
| 36C | 14C |
| 36D | 14D |
| 36DD | 14DD |
| 36DDD | 14E |
| 38A | 16A |
| 38B | 16B |
| 38C | 16C |
| 38D | 16D |
| 38DD | 16DD |
| 38DDD | 16E |
| 40A | 18A |
| 40B | 18B |
| 40C | 18C |
| 40D | 18D |
| 40DD | 18DD |
| 40DDD | 18E |
| 42A | 20A |
| 42B | 20B |
| 42C | 20C |
| 42D | 20D |
| 42DD | 20DD |
| 42DDD | 20E |
Frequently Asked Questions
- What is US women's bras size 40B in AU?
- US women's bras size 40B is equivalent to AU size 18B.
- Is US size 40B the same as AU size 18B?
- Yes, US size 40B and AU size 18B are equivalent in women's bras sizing. However, fit may vary slightly between brands.
- What if US size 40B is too small — what's the next size up in AU?
- The next size up from US 40B is US 40C, which converts to AU 18C.