Determining your size
Step 1: The Band
The band measurement is taken under the bust, where the band sits. Take your soft tape measure and wrap it around your body snugly just under your breasts. Keep your arms relaxed and breathe normally. The tape should not be so tight that it’s uncomfortable, but it does need to be snug. Keep the tape parallel with the floor.
Take the measurement in inches.
Step 2: The Bust
The bust measurement is taken around the body at the fullest part of the bust. Typically, that’s at about level with the nipple, but you may have more fullness at the top or bottom of your breasts, so be sure to find the fullest part. Remember to relax your arms and breathe. Make sure the tape isn’t too tight or too loose- you don’t want it cutting in, but you want the tape parallel with the floor.
Step 3: Bra Math
Your measurement from step 1 is your band size. If you measured your under-bust at 36 inches, that’s your band size. If you measured at a 35 or 37, round up or down to the nearest round number.
Your cup size is determined by the difference between your band size and your bust measurement. For every 1 inch of difference, your cup size increases by 1 (starting with “A”). If your first measurement is a 36 and your second measurement is a 44, your bra size would be a 36H. If your second measurement was a 40, your bra size would be a 36D.