Brassiere measurement (also called brassiere size, bra size or bust size) refers to determining what size of bra a woman wears and mass-producing bras that will fit most women. Bra sizes usually consist of a number, indicating a band size around the woman's torso, and one or more letters indicating the breast cup size. Bra cup sizes were invented in 1932 and band sizes became popular in the 1940s.
Bra sizes vary from one manufacturer to another, and from country to country. Women's bodies and breasts may not conform to the sizes offered by companies. As a result, some women have a difficult time finding a properly fitted bra. Up to 80% of women wear the wrong size bra causing 40% to 60% to experience pain of one kind or another.]citation needed[