To calculate the bra size one should subtract the band measurement (step 1) from the cup measurement (step 2). Generally, for each inch in difference, the cup goes up by one size
Example:
Step 1: 34" under measurement + 4" = 38" band
Step 2: 40" over measurement
Step 3: 40" - 38" = 2" or Cup "B"
The following table reveals the standard Cup size of every bra with a given difference in every individuals size.
The Difference in measurement:
|
The Standard Cup Size
|
| 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 * |
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.