Ratio of the number of live births in a given period from women in a given age to the total number of women in the same age.

Age-specific fertility rates are calculated for individual years of the female reproductive age (15–49) or for 5-year age groups.
Births from women in the age 15 and less are counted to the age of 15, and births from women in the age 50 and more to the age of 49.
Age-specific fertility rates are calculated for periods not shorter than one year. The value is given for 1000 (seldom for 100) women of a given age.

• Generalfertility rate