Teenagers and women have all different sizes of breasts. Pre-teenage girls begin with a “training bra” (trainer bra or bralette), first marketed in the 1950s, which is a brassiere for girls in puberty who are just beginning to develop breasts. Training bras give support to expanding tissue, reduce discomfort associated with puberty, make a girl feel less self-conscious, and is often a ‘rite of passage’ into teen years.
Bra sizes include the chest circumference (in the USA this is given in inches), along with “cup” size. The chest measurement starts at 26-inches and up. The cup covers the breast tissue from top to chest wall under the breast and from side to mid center of the chest. Cup sizes begin at “A”. Letter A are the smallest and each additional letter indicates a smaller cup. All that means, though, is less fabric is included in the bra because the breast tissue will not fill the regular A-B-C cup size. So each letter added means ‘smaller’.

Cup sizes include:

  1. AAA-cup (very small)
  2. AA-cup (smaller)
  3. A-cup (small)
  4. B-cup (medium) — A “B” is considered an average size.
  5. C-cup (larger than B) — A “C” is considered an average size.
  6. D-cup (large)
  7. DD-cup (very large)
  8. Bras can continue from E to Z, the largest.

Bra sizes run from 26AAA (triple A) to 102-ZZZ (triple Z). An average size is 32 to 34 inches in teens to 34 to 36 for adult women. Average cups though run from (single) A to C.

Women with larger breasts are often–but not always–larger build all over.

NOTE 1: There is NO difference in FUNCTION between small or large breasts. ALL size breasts can nurse a baby and provide adequate stimulation during sex. The main differences in larger breasts is that tissue over the chest wall can hide lumps and cysts, and the tissue weight can cause upper back to low back pain, shoulder pain, and draw unwanted attention and emotional pain to women.

NOTE 2: Girls need to know they will not reach their adult size until about mid-teen years. By 15-16 years old, breast tissue stops forming as growth hormones stop and sex hormones begin to level out. Breasts can feel “fuller” during menstrual cycles. Breasts increase in size during pregnancy as a result of hormones that support the pregnancy. Women often do not lose all the extra size after pregnancy, especially if they also gained a lot of weight when pregnant. Breast size also seems to reduce, and is first noticed in the breasts, when a woman loses a lot of weight.
They come in all sizes, but is your bra size -“C”, “D”, etc.