More on bra sizing: "The band size is an estimate of how the breasts should rest on the body. If the breasts are higher, fuller, and protrude in front of the body, the band size should be lowered by as much as two to three inches. If the breasts are wider across the chest (common after breastfeeding) then the bandsize may need to be increased by one or two inches." (posted in the gbook by Dwiv). Well that explains something I've wondered about - how sometimes after breast augmentation surgery, a woman's bra band size can move up. It's because after the operation the breasts are often wider across their chest than previously.