STEP ONE - FIND YOUR BAND SIZE
To find your band size, take a measuring tape and measure around the lower bust (as pictured below), where the band of your bra would sit. Do not measure to tight and leave enough room to breathe. Always round up odd numbers to the next even number, so a 35" would be a 36".
STEP TWO - FIND YOUR CUP SIZE
Measure the fullest part of your bust, evenly and comfortably. Take your band measurement and subtract that number from your bust measurement. To be accurate, take this measurement three times - while standing up, while lying down, and while leaning over.
STEP THREE - FIND YOUR BRA SIZE
Determine your bra size by consulting the chart below.