Finding your bra size doesn’t have to be complicated. With just two measurements—your band and your bust—you can calculate your true size in minutes.
This calculator works for US, UK, and EU sizing systems, so you’ll always know your size no matter where you’re shopping.
How to Use This Calculator
- Measure your band size (underbust, snug but not tight)
- Measure your bust size (fullest part, not compressing tissue)
- Subtract band from bust to find your cup size
- Use the chart below to find your size across all systems
For the full step-by-step method with photos, see How to Measure Your Bra Size at Home.
Bra Size Chart
| Band | Bust Difference | US | UK | EU |
|---|---|---|---|---|
| 28 | 1″ | 28A | 28A | 60A |
| 28 | 2″ | 28B | 28B | 60B |
| 28 | 3″ | 28C | 28C | 60C |
| 28 | 4″ | 28D | 28D | 60D |
| 30 | 1″ | 30A | 30A | 65A |
| 30 | 2″ | 30B | 30B | 65B |
| 30 | 3″ | 30C | 30C | 65C |
| 30 | 4″ | 30D | 30D | 65D |
| 32 | 1″ | 32A | 32A | 70A |
| 32 | 2″ | 32B | 32B | 70B |
| 32 | 3″ | 32C | 32C | 70C |
| 32 | 4″ | 32D | 32D | 70D |
| 34 | 1″ | 34A | 34A | 75A |
| 34 | 2″ | 34B | 34B | 75B |
| 34 | 3″ | 34C | 34C | 75C |
| 34 | 4″ | 34D | 34D | 75D |
| 36 | 1″ | 36A | 36A | 80A |
| 36 | 2″ | 36B | 36B | 80B |
| 36 | 3″ | 36C | 36C | 80C |
| 36 | 4″ | 36D | 36D | 80D |
| 38 | 1″ | 38A | 38A | 85A |
| 38 | 2″ | 38B | 38B | 85B |
| 38 | 3″ | 38C | 38C | 85C |
| 38 | 4″ | 38D | 38D | 85D |
A note on accuracy: The accuracy of your calculated size depends entirely on the precision of your measurements. For the most reliable results, measure to the nearest ¼ inch.
International Size Conversion
For a complete conversion across all sizing systems, see our US vs UK vs EU Bra Size Conversion Chart.
Conclusion
Your size is just a starting point. Different brands and styles may fit differently, so always use your calculated size as a guide—and don’t be afraid to try sister sizes!