I'm fourteen years of age and of average weight and height, but my breasts make me feel so much larger. All the girls in my classes have either B-cups or C-cups, but I have a D-cup. Is this normal? Are they too big for my age? Is there even an average cup size for fourteen year olds?
The size and shape of the human body is variable between individuals. Unfortunately, the measuring of breasts size is also variable. Just as there are people who like really tight slacks and others who prefer a loose fit, people buy bras based more on preceived comfort than actual size. There are two aspects to measuring breasts. The first measures the inches around the chest and is called the band size. Using a cloth measuring tap just underneath the breasts you take the number of inches rounded to the nearest inch. If the number is odd, add 5 to it. If the number is even, add 4 to it. The result is always an even number. Then you measure around the chest at the fullest part of your breasts. Subtract the band size from the answer. A one is an A-cup, two is a B-cup, three is a C-cup, and four is a D-cup. This then gives you a starting point for finding the bra size that you find most comfortable.
The average woman has a 34B size, though different areas of the world are larger or smaller. A C size is considered "ideal" in America. A D size is perfectly normal. There is no correct or best size.
Breast size is not just determined by genetics. How much you weigh has a great deal to do with your size since the breasts store quite a bit of fat.