Now, go to a store and try on your new size. The band should fit snugly on the loosest hook (you tighten as the bra stretches). The center gore (that little piece between your cups) should lie flat against your sternum—if it’s floating, the bra is too small.
Bra Size Calculator & Chart by HSIA
Jump around a little. Do a shimmy. Raise your arms. The straps should stay up without digging in. If any part of this feels like a hostage situation, that’s not your size. Try the sister size (same cup volume, different band) until your body goes “Ahhhh.”