Excess breast fat: Choose a cup size one size larger. (For example, if the difference is C, usually choose D.)
Ambiguous difference: Choose a cup size one size larger to allow room for breast development. (For example, if the difference is 15, between C and D, usually choose D.)
Flat, loose breasts: The smaller the difference, the larger the cup size should be. (For example, if the difference is B cup after properly shaping the breasts using proper fitting techniques, then choose a C cup.)
The horizontal circumference around the highest point of the breast (nipple) is your upper bust measurement. If the measurement is a decimal, round up. For example, 72.1 cm should be calculated as 73 cm.