To determine your band size and cup size, you'll need to take two measurements while wearing a good-fitting, unpadded bra. For the band size, measure around the body, just under the arms, with a measuring tape. Remember to stand up straight and breathe normally. If the measurement is an uneven number, round up to the next even number.

To determine your cup size, you'll need to measure around your body at the fullest part of the bust. Be certain the measuring tape is secure against your back.

Subtract the first measurement (the underarm measurement) from the second measurement (the bust) and look at the chart below to determine your cup size.