Clothing & Fashion
Enter your underbust and bust measurements to find your bra size.
Your Bra Size
32C
Sizing varies by brand; always try on before purchase.
Bra sizing varies significantly by brand and style. Use this calculator as a starting point, then try on sizes nearby (up/down one band or cup) to find the best fit.
Bra sizing consists of two components: the band size (circumference under the bust) and the cup size (volume of the bust). The band size in US sizing is rounded to the nearest even number (32, 34, 36, etc., in inches), and cup sizes range from A to K, with each size representing approximately 1 inch of difference between bust and underbust measurements. This calculator helps you find these numbers quickly.
Measure your underbust (the circumference directly under your bust where a bra band sits) and your full bust (at the fullest part of your chest). Enter both measurements in either inches or centimetres. The calculator rounds your underbust to the nearest even number for the band size and calculates your cup size based on the difference between bust and underbust. For example, a 32-inch underbust with a 35-inch bust gives a 1-inch difference, which corresponds to a cup size A, resulting in a 32A size.
Band Size = Round underbust to nearest even number; Cup Size = Bust – Underbust (1 in = A cup, 2 in = B cup, 3 in = C cup, etc.)The underbust measurement is rounded up or down to the nearest even number because bra bands come in even sizes (32, 34, 36, 38, 40 inches). Each additional inch of difference between bust and underbust increases the cup size by one letter (A, B, C, D, DD, E, F, etc.). This standardised system is used across most major brands.
| Input | Result | Notes |
|---|---|---|
| Underbust: 32 inches, Bust: 35 inches | Bra Size: 32C | A 3-inch difference equals a C cup. Common size for smaller frames. |
| Underbust: 36 inches, Bust: 40 inches | Bra Size: 36D | A 4-inch difference equals a D cup. Middle range band with fuller bust. |
| Underbust: 30 inches, Bust: 32 inches | Bra Size: 30B | A 2-inch difference equals a B cup. Smaller band and moderate bust. |
Each cup letter represents a 1-inch increase in the difference between bust and underbust. DD is a special size (2 inches larger than D); after DD, cup sizes continue with E (3 inches larger than DD), F, G, etc. Some brands use DD interchangeably with E.
Try one band size up or down and one cup size up or down. If the cup is too loose, try a smaller cup or smaller band. If the cup is too tight, try a larger cup or larger band. Fit varies by brand and style, so trying multiple sizes is normal.
Sizing can vary between brands due to different construction and fit philosophies. Your calculator size is a starting point; always try on before buying. Some brands run small or large, and different styles within the same brand can fit differently.
If your underbust is already even (e.g., 34 inches), that's your band size. Round only if your measurement is odd (e.g., 33 inches rounds to 34 inches).
A properly fitting bra: sits level all the way around; the band doesn't ride up in the back; the cup covers all breast tissue without spilling out; straps sit on your shoulders without sliding; and you can fit one finger under the band when fastened. Comfort and support are the ultimate tests.
Having someone else measure is usually more accurate because they can keep the tape level and parallel without your arms getting in the way. However, self-measurement works fine if you're careful to keep the tape level and not pull it too tight or leave it too loose.