I am constantly amazed that so few women understand how bra size is determined. In fact, over 85% of women actually wear the wrong size bra. This is why I never ask what bra size a woman is seeking with cosmetic surgery. The most accurate test for me is to look at photos of my patients with similar body types and determine which ones the patient likes. This way, if I think it is a C and the patient thinks it is a B or D it does not matter. She gets the look she wants.
Another complicating factor is that all bra manufacturers have a different fit and size, so a 36C can be different from maker to maker. So how do you measure bra size?
Step one- With a tape measure, measure the distance around your chest just below the breast. If it is an even number, add 4, iif it is odd, add 5. This is the back size of your body.
Step two- now measure the distance around the breasts while wearing a bra.
Step three- subtract the back size from the breast size. Every inch equals a cup- 1” A, 2”B, etc. After D, the measurement is less accurate.
Hope this helps.