How to Find Your Perfect Bra Size (Without a Fitting Room)

Start with two measurements

Most fit issues come down to guessing instead of measuring. Wrap a soft tape snugly around your ribcage, just under the bust, to get your underbust measurement — this becomes your band size. Then measure around the fullest part of your bust for your bust measurement.

Work out your cup size

Subtract your underbust measurement from your bust measurement. The difference in inches maps to a cup letter — roughly 1" is an A cup, 2" a B cup, 3" a C cup, and so on. Check our full band and cup chart on the Style Guide page for the complete breakdown.

Signs you're in the wrong size

• The band rides up at the back instead of sitting level
• Underwire digs in at the sides or center front doesn't lie flat
• Straps constantly slip or dig into your shoulders
• Cups gape or spill over — both point to the wrong cup size

If in doubt, size up in the band and down in the cup for the closest match — most people find comfort improves within one adjustment.