The "gore" (the center part between the cups) should sit flat against your chest bone. How to measure your bra size
Wrap a soft measuring tape around your ribcage, directly under your bust. Keep the tape level and snug against your skin, but not digging in. This is usually your band size.
A new bra should fit perfectly on the loosest hook . As the elastic stretches over time, you can move to tighter hooks.
Wrap the measuring tape around the fullest part of your chest (usually across the nipples). Ensure the tape is straight across your back and not tilted. Round this measurement to the nearest whole number. 3. Calculate Your Cup Size
Subtract your from your bust measurement . Each inch of difference corresponds to a cup size: 1-inch difference: A cup 2-inch difference: B cup 3-inch difference: C cup 4-inch difference: D cup 5-inch difference: DD/E cup
Some guides, like the Bra Fit Guide from Shyaway , suggest adding 4 inches to your underbust measurement if it's even, and 5 if it's odd, to reach your band size. 2. Measure Your Bust Size
You should be able to fit two fingers under the band comfortably.