What is the right way to measure bra size?

A girl hooking her pink lace bra at the backGillian writes, “I am currently wearing a 34A that I don’t even BEGIN to fill out. Imagine my shock when, using the bra size measurement directions, I discovered that my correct bra size is a 34C!! I thought, well, maybe I measured or added something wrong, so I did it again. Mine don’t even touch a C cup bra no matter how hard I try to squeeze some cleavage out of them, so I know they’re nowhere NEAR a C-D. What is going on with this thing?”

I should have actually added a note at the bottom of the article (which I am now going to) to say that these calculations are just a starting point and in the end one should either get a fitting expert to measure you or keep trying different combinations till you get it right. Not all women are the same and a 34C bra from all manufacturers is not the same. The measurement is also a little complex for women like you that are just 29 at the ribcage.

I am a bit surprised that you do not even fill a 34A because a 3 inch difference is pretty substantial.

Is there a way for you to get yourself measured professionally?