Measure around your bra directly under your bust. Assure the tape is snug, smooth across the back, and parallel to the floor, resting on the lower band of your bra. Round to the closest whole inch up or down.
Add 5 to this measurement to obtain your band size. For example, if your under bust measurement is 29” - add 5 (29+5=34). Your band size is 34.
If the resulting band size is an odd number like 33”, you can usually go to the next band size (34”), but you should also try the next lower band size (32”).
2. Measure Your Cup Size
Measure around the bust at the fullest point. Hold the tape measure straight but make it a loose measurement, not tight.
The difference between this measurement and your BAND size is your CUP size. Each inch of difference is equal to one cup size. For example, if your band size is 34” and your bust measurement is 35”, you wear an “A” cup.