This is one of the best sites for determining your bra size. Most people will be shocked by what it tells them. But then, 90% of women in the US are wearing the wrong bra size. Realistically speaking, you're wearing a sister size, like I am.
The majority of women wear an incorrect size when it comes to bras. This site has a lot of information about bra fit and size. It makes sense once you think about it. I knew my bras didn't fit perfect but I always thought they were close enough. Boy was I wrong. It may seem unbelievable at first, but try the calculator... then go try out a bra in the recommended size. MIND BLOWN. Best fit ever.
Bra calculator Great bra size calculator on this web site for you ladies that might be interested. Too many women wear the wrong size bras which can lead to back problems among other things. You don't have to be large breasted to suffer from back issues. Find good fitting bras and avoid those mega padded Victoria's Secret type bras that basically hang large foam balls from your neck and shoulders. You don't need to fake your size, you just need to love yourself how God made you ;-)