** We strongly advise that you use your actual measurement since it will give you a more accurate size than your bra size.
We still added an approximate bra size as a reference but remember that bra sizes can vary between stores so the real measurement is better.**
For the underbust measurement
Your measuring tape should be very tight on your body
For the full bust measurement
You should wear a bra which is not padded and the measuring tape should be comfortable around your body (not too tight)