1. Band Size
Using a soft tape-measure, measure tightly around your body directly below your bust, resting the tape on the lower band of your bra. Make sure the tape is snug and straight, in front and back.

Add 5 to this measurement to obtain your band size. For example, if your bustline measures 29, add 5 to equal 34.” If your band size is an odd number (ex. 33”), round up to the next even band size (34”), although you may also want to try the lower band size (32”).

2. Cup Size
Now loosely measure around the fullest part of the bust, making sure the tape is straight and not too tight. Each inch of difference equals one cup size. For example, if your band size is 34” and your bust measures 36”, you wear a B cup (2” = B).