This website makes three points about average
breasts. (1) The Average Bust Size
for American women is 35.9 inches (91.2 cm). The typical bra size is 35B, with the proportions of women's cup sizes breaks down to the following: A-15%, B-44%, C-28%, D-10%, while the remaining 3% are AA, AAA, DD and beyond." But did you know that if you wear a 36C, your breasts weigh roughly a pound apiece? (An A cup is closer to half a pound). (2) "Interestingly, manufacturers of women's clothing agree that the average American woman's bust size has expanded in recent decades, if only by fractions of an inch, due to improved diet and birth control pills." But did you know that breasts are made of roughly 50 percent glandular tissue and 50 percent fat; but for those with a D cup or larger, about 70 to 80 percent fat? That's because breasts and fat work as a team; buy one, you get the other free. (3) The diameter of "average areola (dark part around nipple) is 1.4 inches (35.62 mm)". But did you know it may be three-plus in the larger-breasted?