Wear a non-padded bra or no bra
Measure around the fullest part of your bust
Keep the tape measure level and snug, but not tight
Measure around your ribcage directly under your bust
Round both measurements to the nearest whole number
Subtract the band measurement from the bust measurement
Use the difference to find the cup size
1 inch difference = A cup
2 inches difference = B cup
3 inches difference = C cup
4 inches difference = D cup
5 inches difference = DD or E cup
6 inches difference = DDD or F cup
Check the brand’s size chart for exact sizing