Bra & cup size calculator
Two measurements give you your band and cup size, the same numbers a size sheet and a fitting call ask for. Enter your underband and bust in centimetres or inches and get your size in India / UK, US and EU at once.
Your measurements
Measure the band snug and level around your ribcage just under the bust, then the bust around the fullest part. Stand relaxed, unpadded.
Band and cup vary by brand and by fitting method (this uses the modern round-to-nearest-even-inch band, with no inches added). Treat the result as a starting guide and confirm with a proper fitting before a job.
How your size is worked out
Your band is the number, taken from your ribcage measurement just under the bust. Your cup is the letter, taken from how much larger your bust is than your band: about one inch of difference is an A cup, two inches a B, three a C, four a D, and so on. India follows UK sizing exactly, so an Indian 34C is a UK 34C. The calculator rounds the band to the nearest even inch using the modern method, which adds nothing to the measurement.
Cup size by difference
The cup comes from the gap between bust and band. US matches India / UK up to a DD, then changes letters; EU uses single letters after D.
| Difference | India / UK | US | EU |
|---|---|---|---|
| 0" | AA | AA | AA |
| 1" | A | A | A |
| 2" | B | B | B |
| 3" | C | C | C |
| 4" | D | D | D |
| 5" | DD | DD | E |
| 6" | E | DDD | F |
| 7" | F | G | G |
Band size from your underband
| Underband (cm) | Underband (in) | India / UK / US | EU |
|---|---|---|---|
| 63 to 67 | 26 to 27 | 28 | 60 |
| 68 to 72 | 27 to 28 | 30 | 65 |
| 73 to 77 | 29 to 30 | 32 | 70 |
| 78 to 82 | 31 to 32 | 34 | 75 |
| 83 to 87 | 33 to 34 | 36 | 80 |
| 88 to 92 | 35 to 36 | 38 | 85 |
| 93 to 97 | 37 to 38 | 40 | 90 |
| 98 to 102 | 39 to 40 | 42 | 95 |
The rest of your measurements
Bust and cup are two lines on a longer size sheet. Convert height, body measurements, weight and shoe size with the measurement converter, and read the measurements every modeling agency asks for to take each one correctly at home.
Frequently asked questions
- How do I calculate my bra size at home?
- Measure two things with a soft tape. First the underband, snug and level around your ribcage just under the bust, that gives your band size. Then the bust around the fullest part. The difference between the two, in inches, gives your cup: about 1 inch is an A cup, 2 inches a B, 3 inches a C, 4 inches a D, and so on. The calculator above does both steps for you in centimetres or inches.
- What is the difference between band and cup size?
- The band is the number (32, 34, 36) and comes from your ribcage measurement just under the bust. The cup is the letter (A, B, C, D) and comes from how much larger your bust is than your band. A 32C and a 34C have the same cup letter but different band widths, so both parts matter.
- Is Indian bra sizing the same as UK?
- Yes. India follows UK sizing for both band numbers and cup letters, so an Indian 34C is a UK 34C. US sizing matches for AA to DD and then uses different letters above that, while EU uses different band numbers (a UK 34 is an EU 75) and single letters after D. The calculator shows India / UK, US and EU together.
- Why do models need to know their cup size?
- Band and cup go on your size sheet and comp card alongside bust, waist and hips. For lingerie, swimwear, bridal and fitting work, stylists and designers pull garments by size before you arrive, so a model who knows her exact band and cup is quicker to dress and books fittings with less back and forth.
- How accurate is this bra size calculator?
- It uses the modern band method (underband rounded to the nearest even inch, with no inches added) and the standard cup-difference scale. Real fit still varies by brand, cut and fabric, so treat the result as an accurate starting point and confirm with a proper fitting before a paid job.