Fertility fell. How low did it go?

All six selected series end below their 1960 values. Between those endpoints, the declines were not equal: South Korea fell by 5.246 births per woman, India by 3.959, and China by 3.438. Nigeria’s rate also fell, by 1.982, while remaining at 4.382 in 2024. These are changes in the WDI series, not explanations for why they happened.

Five of the selected series first move from above to at-or-below 2.1 between adjacent annual observations in this vintage: France in 1975, the United States in 1972, South Korea in 1983, China in 1991 and India in 2020. Nigeria has no such downward crossing through 2024. The 2.1 benchmark is a rough reference often associated with replacement fertility under low mortality; it is not a universal dividing line. Mortality matters, and the UN’s population momentum note explicitly takes mortality levels into account when measuring replacement.

A period fertility rate below that reference does not make a population instantly shrink. Population momentum can persist because many people are still at childbearing ages; migration and mortality also affect population totals. These six lines cannot establish a global lowest-rate ranking, forecast a population decline, or identify a cause. The United States’ small 2024 increase is a reminder that a long-run decline need not move down every year.

Source: World Bank World Development Indicators API, indicator SP.DYN.TFRT.IN (Fertility rate, total), South Korea, China, India, Nigeria, France and the United States. The API response was retrieved on 10 October 2026 and reports an update on 8 October 2026. See the World Bank’s indicator metadata for the definition and source organizations. WDI identifies the United Nations Population Division’s World Population Prospects, national statistical offices and Eurostat among its sources.

Total fertility rate is a hypothetical period measure: it represents the number of children a woman would have if she experienced the age-specific fertility rates observed in a particular year throughout her childbearing years. It is not the number of children women actually have, annual births, or a crude birth rate per population. WDI’s API returned 65 non-null annual values per country for 1960–2024. It also returned a 2025 row for each country, but all six values were null, so 2025 is excluded and listed as missing in the source validation.

WDI notes that some annual UN series interpolate five-year data; these curves should not be read as precise annual events. The native animation interpolates between annual observations for motion; transitional frame values are not extra observations. The table rounds to three decimals for display. The downloadable CSV preserves the decimal values returned by WDI without unit conversion; changes are calculated before rounding. This is one retrieved vintage of an estimate series and may be revised. Its six selected countries do not support a worldwide ranking. The source is made available under CC BY 4.0; attribution: World Bank, World Development Indicators, SP.DYN.TFRT.IN; changes: selected six countries and formatted comparison. The UN population momentum note explains that replacement levels also account for mortality. The illustration is decorative and does not encode or source the data.