Well, the cup lecture, in my practice, goes like this: People who make bras do not do breast surgery, so there's no medical grade designation for cups. A cup size is determined by the manufacturer of the bra and they don't ask us what size we put in to correspond with the implant size. So, I try to dissuade the patients away from cup size as a final measurement of their happiness and their satisfaction. I try to get them to lean more toward how you feel, so we have the implants out so they feel them, we size them, where the girls go through a sizing process. They put in different implants to see how they feel and live with it for a few minutes to get an idea of what really appeals to them in their heart of hearts. Once we get that, then it really doesn't matter what cup size they were.

Leave Cup Size Out of It: A Look Into the Breast Implant Sizing Process

"People who make bras do not do breast surgery," says Dr. Thomas Trevisani. For this reason, cup size should never be used in a proper breast implant sizing process.