Small guide to not make a mistake, and buy well on the internet.
Knowing your cup size
First, you need to measure your bust size yourself with a tape measure. To then know your cup size, you must first measure your chest size from the tip of your breasts, then subtract your bust size from this number: – if the difference is 10 cm, you make an A cup. – if the difference is 15 cm, you make a B cup. – if the difference is 17.5 cm, you make a C cup. – if the difference is 20 cm, you make a D cup. – if the difference is 22,5 cm, you make a cup E. The right cup should be neither too big nor too small: your breasts should fill it correctly, without overflowing or showing your nipples.
Bra size matching
For the cups, if in doubt, take a size down if you order in the USA. Ex 90B -> 34A. Then there are several strategies to then enhance your cleavage and choose the right bra.