How do you know what your cup size is?
Ethan Hayes
Published Jan 06, 2026
Measure loosely around the fullest part of your bust. Subtract the band size from this measurement. Use this number to determine your cup size according to the table below. Example: if your ribcage measurement is 31, and your bust measurement is 37, your bra size is a 34C: 31+3=34, so 34 is your band size.