Calculate general, age-specific, or total fertility rates from annual birth and population data, with results per 1,000 women or children per woman.

Use births and midyear populations from the same place and year.

Use the age convention of the statistic you are reproducing.

Crude birth rate (optional)
Optional: adds the crude birth rate (births per 1,000 people).

General Fertility Rate Formula

The following two example problems outline the steps and information needed to calculate the General Fertility Rate.

FR = LB / P × 1000
  • Where FR is the General Fertility Rate (births per 1000 women)
  • LB is the number of live births 
  • P is the midyear female population ages 15-44 from the same geography and year as the annual live births 

To calculate the general fertility rate under the US convention, divide annual total live births by the midyear female population ages 15–44 from the same place and year, then multiply by 1000. The calculator also offers a 15–49 denominator; use the convention of the source statistic. ASFR uses births to and the population of the same age group. TFR uses five times the sum of seven annual five-year ASFRs (15–19 through 45–49), divided by 1000 when the rates are per 1000 women. It is a synthetic period measure, not individual fertility or a pregnancy probability.

How to Calculate General Fertility Rate?

The following example problems outline how to calculate General Fertility Rate.

Example Problem #1:

  1. First, determine the number of live births.
    • The number of live births is given as 100,000.
  2. Next, determine the female population ages 15-44.
    • The female population ages 15-44 is provided as 2,000,000.
  3. Finally, calculate the General Fertility Rate using the equation above: 

FR = LB / P * 1000

The values provided above are inserted into the equation below and computed.

FR = 100,000 / 2,000,000 * 1000 = 50 (births per 1000 women)

Example Problem #2: 

For this problem, the variables required are provided below:

number of live births = 150,000

female population ages 15-44 = 3,000,000

Test your knowledge using the equation and check your answer with the calculator.

FR = LB / P * 1000 = ?