In 1990, 60 of the world's 237 countries and territories had a total fertility rate (the average number of children a woman would have at that year's birth rates) below 2.1, roughly the replacement level at which each generation replaces itself. By 2023 it was 130: more than twice as many, and more than half. The number below 1.4, a level the UN calls "ultra-low", went from 5 to 43, holding a quarter of the world's people, mostly in China.
These are the UN's latest estimates, for 2023; the next edition has been postponed to 2027. Some national figures have moved since: South Korea's rose slightly in 2024, to 0.75, according to Statistics Korea.
The fall did not stop at replacement: most places already below it in 2010 were lower still by 2023. In sub-Saharan Africa, where the fall is far from finished, there are now almost a third of the world's births.
Countries and territories with a total fertility rate below 2.1 and below 1.4 children per woman, 1950–2023. Data: UN World Population Prospects 2024.
What these numbers are
The total fertility rate is how many children a woman would have if she lived through her childbearing years at one year's birth rates for each age. It describes a year, not any real woman: when people have children later, the rate dips even if they end up with as many.
Replacement is the rate at which each generation, without migration, is replaced by one of the same size. Where few children die young, it is about 2.1. We use 2.1 as a common benchmark; actual replacement fertility varies with mortality and sex ratios.
All charted figures are UN estimates for 1950–2023; the charts use no projections. These are harmonized UN estimates, sometimes modelled, and may differ from national registration figures. All 237 series the UN publishes are kept, including tiny ones such as the Holy See, whose rate the UN fixes at 1.
The places below 2.1 held 24% of the world's people in 1990 and 67% in 2023. Most of that rise is two countries: China went below 2.1 in 1991 and India in 2020. Outside those two, the share went from 38% to 49%. Among places of a million or more people, 81 of 161 are below 2.1.
It took about a generation
Years from the last year at five or more children per woman to the first year below 2.1. Data: UN World Population Prospects 2024.
Of 37 countries and territories with at least one million residents in 2023 that fell from five children per woman to below 2.1, the median time taken was 31 years. Iran took 10, China 19 and South Korea 20; India took 43 and Sri Lanka 51.
This counts only falls that reached 2.1; 8 of the 37 have since risen back above it. Most of Europe, the United States and Japan were already below five in 1950, when the record starts, so their own falls cannot be timed here.
It did not stop at 2.1
Total fertility rate in 2010 and 2023, selected countries. Data: UN World Population Prospects 2024.
Of the 103 places already below 2.1 in 2010, 87 were lower in 2023; 72 of those 87 were already lower by 2019, before COVID. South Korea went from 1.23 to 0.72; only Macao and Hong Kong are lower, on unrounded estimates (Hong Kong and South Korea both round to 0.72). China fell by 0.69, to 1.00.
The fall also hit countries whose rates had been stable since about 1990, such as the United States, Finland and Norway. The United States went from 1.92 to 1.62; Finland fell by 0.58 and Norway by 0.54. Half of the 16 places that did not fall are in central and eastern Europe: Bulgaria, Bosnia and Herzegovina, Hungary, Moldova, Montenegro, Romania, Serbia and Slovakia. Hungary rose from 1.26 to 1.49. This data cannot say why. Hungary expanded family tax breaks in 2011–2012 and introduced housing subsidies in 2015; these descriptive comparisons cannot establish how much those policies contributed to the rise.
Where the fall is far from finished
Each region's share of the world's births, 1950–2023 (UN SDG regions; the two Oceania groups combined). Data: UN World Population Prospects 2024.
Sub-Saharan Africa's rate is falling too, but was 4.32 in 2023, against 2.25 worldwide. Its share of the world's births nearly doubled, from 15.5% in 1990 to 30.4%. Part of that is its growing share of the world's people, 9.4% to 15.0%; births grew faster, to twice its population share. East and South-East Asia went the other way, from 29.9% of births to 15.7%.
Why it matters
Sustained fertility below replacement makes populations older and, without migration, eventually smaller. On its medium projection, the UN expects the world's population to peak at around 10.3 billion in the mid-2080s; that is a projection, not a finding of this data.
Why, according to others
This data shows rates, not reasons. Others' explanations, untested here:
For the long fall from about five children, Max Roser of Our World in Data credits "women's empowerment, declining child mortality, and the rising cost of bringing up children".
The UN Population Division says that in several low-fertility countries women have fewer children than they expected, naming obstacles including "high costs of childcare, challenges to work-family balance" and an "unequal division of household tasks between partners".
For the United States, the economists Melissa Kearney, Phillip Levine and Luke Pardue found that the Great Recession explains part of the early fall. Studying 2007–2020, they could not identify another economic, policy or social factor explaining much of the subsequent decline; they conjectured that younger cohorts' priorities had shifted.
For the Nordic countries, Julia Hellstrand and colleagues found that postponement explains only part of the decline; their 2021 forecasts put average Nordic completed fertility around 1.8 children for late-1980s cohorts, with Finland below 1.6.
How this was made
The data is the UN's World Population Prospects 2024, medium variant: estimates for 1950–2023 (2023 is the latest estimate year in this edition). It is still the current edition; the UN has postponed the next one to July 2027. fetch.mjs downloads it, checks its hash and writes two small extracts (countries, regions); calculate.mjs computes every number in this post; birth-rates-make-charts.mjs builds the charts, and re-running it reproduces them exactly. World Bank figures, which draw partly on the same UN estimates, differ by at most 0.064 children per woman across 36 comparisons (16 countries plus the world and sub-Saharan Africa, in 2010 and 2023). Licence and choices: PROVENANCE.md and DATA.md. From the download folder, run:
npm ci
node birth-rates-src/calculate.mjs
node birth-rates-make-charts.mjs