Follow our steps and get that measuring tape out. The method below is called the Formula Fit and is most effective on smaller cup sizes (A-C).
As the breast gets fuller, measurements can become more variable.
Step 1: Band measurement
Place the measuring tape just under your bust and around your ribcage, making sure it sits at the same height all the way around your torso. This will give you your band size.
Step 2: Cup measurement
Again, making sure the tape is level in your front and back, hold it around the fullest part of your breast. Remember not to hold too tight.
Step 3: Calculate your bra size
Subtract your band measurement from your cup measurement and then find the resulting number in the table below to find out what cup size you should be wearing.