Measuring for a bra can be done easily. First put on your best fitting bra. Next use a flexible tape measure and measure around your ribcage right underneath your bra. Add 5 to this number. This is your band size. Next measure around the fullest part of your chest. This is your cup size. Subtract your band size from your cup size. The differnce will give you yor cup. 1 in difference is A cup, 2 is B cup, 3 is C cup 4 is D cup, 5 is E cup, 6 is F cup. It can keep going up from there.