Measure & Calculate Your Size
1. Measure your rib cage.
To start, be sure to wear a lingerie bra that maintains your natural shape—with little to no padding or minimizing features. Measure around your rib cage around the bottom band, just under the breast. The tape measure should feel quite snug. Round the measurement down to the closest inch.
2. Measure your bust.
Measure the bust over the fullest point of the breast. For larger-breasted women, the fullest point may not be at center, and is often lower. As breast tissue can fluctuate as much as 20%, round up to the closest inch.