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Total Fertility Rate Formula:
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The Total Fertility Rate (TFR) represents the average number of children a woman would have over her lifetime if she experienced current age-specific fertility rates. It is calculated by summing age-specific fertility rates and multiplying by the age interval (typically 5 years).
The calculator uses the TFR formula:
Where:
Explanation: The formula sums the fertility rates across all reproductive age groups (typically 15-49) and multiplies by the age interval to estimate the total number of births per woman.
Details: TFR is a crucial demographic indicator that helps understand population growth patterns, plan social services, and analyze demographic transitions in societies.
Tips: Enter age-specific fertility rates for each 5-year age group from 15-19 to 45-49. All values must be non-negative numbers representing births per woman per year.
Q1: What is a replacement level fertility rate?
A: The replacement level is typically around 2.1 births per woman, which would keep a population stable without migration.
Q2: How does TFR differ from crude birth rate?
A: TFR measures fertility per woman, while crude birth rate measures births per total population, making TFR a more accurate measure of fertility behavior.
Q3: What are typical TFR values worldwide?
A: TFR ranges from below 1.0 in some developed countries to over 5.0 in some developing nations, reflecting different demographic stages.
Q4: Why use 5-year age intervals?
A: Five-year intervals provide sufficient detail while maintaining statistical reliability and are standard in demographic analysis.
Q5: Can TFR predict future population growth?
A: While TFR is a key component, population projections also consider mortality rates, migration patterns, and current age structure.