Everyday Life Calculators

Bra Size Calculator

Estimate band size and cup size from underbust and bust measurements.

Band size —

Cup size —

Estimated size —

About the Bra Size Calculator

This calculator uses a common simplified formula to estimate bra size from two body measurements: underbust (directly under the bust) and bust (at the fullest point).

Formula: Band Size = nearest even underbust inch + 4. Cup Size = one letter per inch of difference between bust and underbust (0" = AA, 1" = A, 2" = B, and so on).

This is a simplified estimate — sizing varies by brand and style, so use it as a starting point rather than an exact fitting.