This means you have a C cup, and your bra size is 34C ... and if the band feels tight try the size to the right of your current one. For example, if you're usually a 34C but the band feels ...
This tells you how much bigger your breasts are than your rib cage (not simply the size of your breasts) and is represented by letters (A, B, C, etc.). To find your bra ... cup letter. So, for ...