TFR

Total Fertility Rate (TFR) is a demographic measure representing the average number of children a woman would bear over her lifetime given current age-specific fertility rates.

It is calculated by summing the age-specific fertility rates for the reproductive ages, usually 15 to 49, across a population, or by constructing a synthetic cohort to simulate lifetime births.

As a period measure, TFR reflects current fertility patterns rather than individual destinies. Differences among countries stem from factors such as education, employment, urbanization, access to contraception and abortion services, child mortality, and social norms.

A replacement-level TFR is about 2.1 children per woman in many developed countries, assuming no net migration and low mortality. Lower mortality or higher migration can shift this figure. Some high-fertility countries have TFR well above replacement, while many low-fertility countries sit well below it. Global patterns show a general decline in TFR over recent decades, though the pace and level of change vary widely by region and policy context.

Data come from censuses, national vital statistics, and household surveys, and TFR is subject to sampling error, delays in reporting, and assumptions about mortality and migration. As a period indicator, it is most informative when interpreted alongside cohort fertility and other demographic indicators.

In other fields, TFR may denote Time-Frequency Representation or other technical terms, but in demography the term most commonly refers to Total Fertility Rate.