A Fertility Rate Calculator is a helpful demographic tool that estimates how many children are born relative to a population. It gives quick results for different fertility measures, such as the Crude Birth Rate, the General Fertility Rate, and the Total Fertility Rate. These measures help governments, researchers, and health planners understand population growth and forecast future resource needs.
formula of Fertility Rate Calculator
1. Crude Birth Rate:
Formula:
Crude Birth Rate = (Number of Births / Total Population) × 1000
This shows the number of live births per 1,000 people in the total population.
2. General Fertility Rate (GFR):
Formula:
GFR = (Number of Births in a Year / Number of Women Ages 15–49) × 1000
This rate focuses only on women who can give birth.
3. Total Fertility Rate (TFR):
Formula:
TFR = 5 × Σ(ASFR)
Where:
- ASFR = Age-Specific Fertility Rate = (Number of Births to Women in Age Group) / (Number of Women in Age Group)
- Σ(ASFR) = Sum of all ASFRs for each 5-year group between ages 15 and 49.
The factor 5 adjusts for each 5-year age band.
Common Reference Table
| Term | Meaning | Typical Value/Unit |
|---|---|---|
| Crude Birth Rate | Births per 1,000 population | 10–50 births/1,000 people |
| GFR | Births per 1,000 women aged 15–49 | 40–200 births/1,000 women |
| TFR | Average children per woman | 1.5–7.0 children |
Use this table for a quick look at the numbers demographers handle.
Example of Fertility Rate Calculator
Example for GFR:
- Number of births in a year: 1,500
- Number of women aged 15–49: 10,000
GFR = (1,500 / 10,000) × 1000
GFR = 0.15 × 1000 = 150 births per 1,000 women
This means that, in this population, there are 150 births for every 1,000 women of childbearing age in one year.
Most Common FAQs
A: A TFR of about 2.1 children per woman is considered the replacement level in developed countries. This keeps the population stable over time.
A: Each rate shows a different part of the bigger picture. The Crude Birth Rate is simple but broad. GFR focuses on women who can give birth. TFR is the most detailed and predicts the average family size.
A: Yes. They can rise or fall due to social changes, economic factors, healthcare access, or government policies.