Bra Size Converter & Calculator
Convert bra sizes between US, UK, EU, French, and Australian sizing systems. Use our band and cup size charts to find your perfect international fit, from 32A through 40DD.
Band Size Conversion
Quick Converter
| US/UK Band | EU Band | FR/ES Band | AU Band | Underbust (in) |
|---|---|---|---|---|
| 30 | 65 | 80 | 8 | 26-27 |
| 32 | 70 | 85 | 10 | 28-29 |
| 34 | 75 | 90 | 12 | 30-31 |
| 36 | 80 | 95 | 14 | 32-33 |
| 38 | 85 | 100 | 16 | 34-35 |
| 40 | 90 | 105 | 18 | 36-37 |
| 42 | 95 | 110 | 20 | 38-39 |
| 44 | 100 | 115 | 22 | 40-41 |
Click any row to highlight it. Sizes are approximate and may vary by brand.
Full Bra Size Conversion (Band + Cup)
Quick Converter
| US | UK | EU | FR | AU | Bust-Band (in) |
|---|---|---|---|---|---|
| 32A | 32A | 70A | 85A | 10A | 1 |
| 32B | 32B | 70B | 85B | 10B | 2 |
| 32C | 32C | 70C | 85C | 10C | 3 |
| 32D | 32D | 70D | 85D | 10D | 4 |
| 32DD | 32DD | 70E | 85E | 10DD | 5 |
| 34A | 34A | 75A | 90A | 12A | 1 |
| 34B | 34B | 75B | 90B | 12B | 2 |
| 34C | 34C | 75C | 90C | 12C | 3 |
| 34D | 34D | 75D | 90D | 12D | 4 |
| 34DD | 34DD | 75E | 90E | 12DD | 5 |
| 36A | 36A | 80A | 95A | 14A | 1 |
| 36B | 36B | 80B | 95B | 14B | 2 |
| 36C | 36C | 80C | 95C | 14C | 3 |
| 36D | 36D | 80D | 95D | 14D | 4 |
| 36DD | 36DD | 80E | 95E | 14DD | 5 |
| 38A | 38A | 85A | 100A | 16A | 1 |
| 38B | 38B | 85B | 100B | 16B | 2 |
| 38C | 38C | 85C | 100C | 16C | 3 |
| 38D | 38D | 85D | 100D | 16D | 4 |
| 38DD | 38DD | 85E | 100E | 16DD | 5 |
| 40A | 40A | 90A | 105A | 18A | 1 |
| 40B | 40B | 90B | 105B | 18B | 2 |
| 40C | 40C | 90C | 105C | 18C | 3 |
| 40D | 40D | 90D | 105D | 18D | 4 |
| 40DD | 40DD | 90E | 105E | 18DD | 5 |
Click any row to highlight it. Sizes are approximate and may vary by brand.
How to Measure Your Bra Size
Wear a non-padded bra or no bra for the most accurate measurement. Use a soft tape measure and keep it level around your body.
Step 1: Band Size (Underbust)
Wrap the tape snugly around your ribcage, directly under your bust. The tape should be level all the way around and firm against your skin without digging in. Round to the nearest whole number. If the number is even, that is your band size. If odd, round up to the next even number.
Step 2: Cup Size (Bust)
Measure loosely around the fullest part of your bust, keeping the tape level. Subtract your band measurement from this bust measurement. The difference determines your cup size: 1 inch = A cup, 2 inches = B cup, 3 inches = C cup, 4 inches = D cup, 5 inches = DD cup.
Understanding International Bra Sizing
International bra size conversion can be confusing because every region uses a different system. US and UK sizes share the same band numbers (in inches) but diverge on cup labeling beyond DD. EU sizes use centimeter-based bands — a US 32 is an EU 70, a US 34 is an EU 75, and so on. French sizing adds 15 cm on top of the EU band, so an EU 70 becomes an FR 85.
Australian bra sizes use yet another numbering system for bands — AU 10 equals US/UK 32, AU 12 equals 34, and AU 14 equals 36. The cup letters follow the UK system. When shopping internationally, always refer to the underbust measurement in inches or centimeters and the bust-minus-band difference for the cup size, rather than relying on size labels alone.
Frequently Asked Questions
How do EU and French bra sizes differ from US sizes?
EU bra sizes use centimeter-based band numbers (65, 70, 75, etc.) instead of inches. French sizes add 15 cm to the EU band number, so an EU 70 becomes FR 85. Cup letters are mostly the same up to D, but beyond that the systems diverge: a US DD is labeled E in EU and French sizing. Italian sizing uses a completely different numbering system.
What are sister sizes and when should I use them?
Sister sizes are bra sizes that share the same cup volume but with different band lengths. For example, 34C, 32D, and 36B are all sister sizes with the same cup volume. If your usual band size feels too tight, try going up one band size and down one cup letter. If it feels too loose, go down one band size and up one cup letter.
How often should I re-measure my bra size?
Your bra size can change due to weight fluctuations, hormonal changes, pregnancy, and aging. It is recommended to re-measure every 6 to 12 months. Signs that your current size is wrong include the band riding up in the back, cups gapping or overflowing, straps digging in, or the center gore not lying flat against your sternum.
Do Australian bra sizes match UK sizes?
Australian bra cup sizes are the same as UK cup sizes, but the band sizes differ. AU band sizes use even numbers starting from 8 (equivalent to US/UK 30). To convert AU band to US/UK, multiply the AU number by a factor or use the chart above. For example, AU 10 equals US/UK 32, AU 12 equals 34, and so on, adding 22 to the AU number.
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