Measure for Your Bra Size:
First measure under the bust. With a measuring tape, measure directly under the bust, positioning the tape tight around your body and level across your back. If the measurement is 35 inches or lower, add 5 inches if it’s an odd number or 4 inches if it’s an even number. If the measurement is 36 inches or more, go to the next even number.
Measure for Your Cup Size
This is best done with a bra on, Gently measure around the fullest part of your remaining breast from the center of the sternum (breastbone) to the center of your spine. Double this measurement.
Calculate the difference between the measurements you took in your Bra Size and your Cup Size. Apply that number to our mastectomy Cup Sizing Chart you can find below.
Under Bust Measurement = 36 inches
The Over Bust Measurement = 19 inches with the doubling method you get 38
The difference between 36 and 38 is 2 inches. As indicated in the Cup Sizing Chart below, a 2-inch (2″) difference equals a B cup.