For example, if your band size is a 34, but your bust is measuring a 38, there’s a 4 point difference: A is 1, B is 2, C is 3, and D is 4. So, in this case, your cup size is a D.

The difference is your U.S. cup size, with “0” corresponding with an AA cup, “1” is an A, “2” is a B and so on. For example, if your band measurement is 34 and your cup measurement is ...

Here’s how to do it: Measure your band size: Measure (in inches) firmly around your ribcage, just below where your bra fits. This will provide your under-band measurement.

An easy step-by-step guide on how to measure your bra size at home using just a tape measure. Calculate your band and cup size to find your true bra size.