STEP 1: Measure for band size:
Keeping the measuring tape parallel with the
ground, measure around your bra directly under
your bust after expelling all air from your lungs -
you want this measurement to be as small as
possible. Round all fractional measurements to the
nearest whole number.
If the measurement is even, add 4"
If the measurement is odd, add 5"
STEP 2: Measure for cup size:
Standing straight, with your arms at your side, measure at
the fullest part of your bust (while wearing a non-padded
bra) making sure the measuring tape is parallel with the
ground and not binding.
Round all fractional measurements to the nearest whole
number.
STEP 3: Calculate your bra size:
Subtract your band measurement (step 1) from your cup
measurement (step 2). Generally, for each inch in difference,
the cup goes up by one size. See the cup size conversion chart
here.
Example:
Step 1: 34" under measurement +4" = 38" band
Step 2: 40" over measurement
Step 3: 40" - 38" = 2" or Cup "B"
Your size would be 38B
If The Difference Is: Your Standard Cup Size Is:
0"-1/2" (1.3 cm) AA
1/2"- 1" (2.6 cm) A
2" (5.1 cm) B
3" (7.6 cm) C
4" (10.2 cm) D
5" (12.7 cm) DD or E
6" (15.2 cm) DDD or F
7" (17.8 cm) G
8" (20.3 cm) H
9" (22.9 cm) I
10" (25.4 cm) J
Important Note: this measuring system tends to become less
accurate as the cup sizes go above a D. Additionally, some
manufacturers name larger cup sizes differently.