Size guide bras for pregnancy & nursing, Boob Design. across the fullest part of your bust (A) and the under-bust measurement (B) gives your cup size.
There was once a time when 34B was the average bra size in the USA. In fact, right from the invention.
Picture of Woman breast size comparison B,C,D,E stock photo, images and stock photography. Image
Fast forward just twenty or thirty years, however, and the average breast size has changed entirely. A number of More women are wearing the same sized b.