The number of children a typical woman has over her lifetime, known as the total fertility rate, has fallen sharply around the world. Our World in Data’s overview, first published in 2014 and based on United Nations population data, documents how far and how fast. This article summarizes what it reports and what it does not.
How far has global fertility fallen?
Up to about 1965, the global total fertility rate was around 5 children per woman. By around 1975 to 1980 it was still close to 4. Our World in Data says it is now below 2.5 children per woman, without giving a precise recent value. The global population growth rate peaked at 2.3 percent a year in 1963 and is now below 1 percent. For the definition, see our entry on the total fertility rate.
What did the world look like in 1950?
In 1950 to 1955, Luxembourg was the only country with a fertility rate below 2 children per woman. China was just over 6, and India just under 6. Today, about 80 percent of the world’s population lives in countries with fewer than 3 children per woman, and about 10 percent lives in countries with more than 5. A footnote in the article says that about 40 percent of the world’s population lives in countries below 2. See our country entries on China and India.
How fast can fertility fall?
The article gives several country examples of rapid change.
- Iran: 6.6 in 1982, 1.8 in 2005 and about 1.7 in 2022
- Thailand: 6.3 in 1950, 2.5 in 1985 and 1.3 today
- Italy: 2.6 in 1966 and 1.2 in 1997
- Brazil: almost 6 in 1965 and below 3 in 1999
- Yemen: 8.9 in 1985
These examples show that the pace of decline varies widely, and that large falls have happened within a generation.
What was fertility like before 1950?
Estimates for Europe before 1790 range from 4.5 to 6.2 children per woman: Belgium 6.2, France 5.8, Germany 5.1, England 4.9, the Netherlands 4.9 and Scandinavia 4.5. These come from secondary sources and a historian’s estimates, so they are less certain than modern figures. The article also cites the Hutterites in early twentieth-century North America at 10.4 children per woman as an extreme example of high fertility.
What do the United Nations expect?
The UN expects the global fertility rate to be just below 2 children per woman by the end of the century. Our article on the world population peak explains how the UN’s projections turn these fertility assumptions into population numbers, and our explainer on aging populations covers one consequence.
What does the measure leave out?
Our World in Data lists several caveats. The total fertility rate is a period measure and not a cohort measure, so it describes one year’s birth rates and not the completed family size of any group of women. It also assumes a hypothetical woman survives her full reproductive life. The article describes claims about the causes of fertility decline as contested or varying by study, so we do not assign a cause.
Glossary: terms used here
- Total fertility rate (TFR): the average number of children a woman would have over her lifetime if she experienced the birth rates of a given year at each age
- Replacement level: the fertility rate at which a population exactly replaces itself without migration, usually put at about 2.1 children per woman in countries with low child mortality
- Period measure: a measure that describes one year’s rates
- Cohort measure: a measure that follows a group of women through their lives
- Population growth rate: the yearly percentage change in total population
These definitions are general ones. The Our World in Data article we read does not mention the replacement level.
A worked example of how to read the rate
Suppose a country’s fertility rate is 1.3, as Our World in Data says of Thailand today. If that rate persisted, each generation would be smaller than the one before, other things being equal. A rate of 6.3, as in Thailand in 1950, implies the opposite. That is simple arithmetic about the definition and is our own illustration. In practice, populations also change through deaths and migration, which is why fertility alone does not decide the population trend.
Why does fertility matter?
Fertility is one of the main drivers of how large and how old a population becomes. When fertility falls, the share of older people in the population tends to rise over time, a pattern known as population aging. When the fall is steep, as in the examples above, the change can happen within a few decades. Falling fertility also relates to falling child mortality, which our article on child mortality documents. The link between the two is general demographic background and is not discussed on the page we read.
How do countries differ?
The examples show a wide spread. The article cites Taiwan at close to 1 in the 2010s, Iran at about 1.7 in 2022 and Kerala, a state in India, at 1.7. It cites China at 1.9 in a comparison drawn from the economist Amartya Sen. Differences of this size exist between neighboring places, which is why a single world average hides more than it shows.
Why does the date matter?
The article was first published in 2014, and the page we read does not give a recent update date. Where it says “today,” we therefore treat the statement as approximate and prefer the UN’s current estimates when they differ. This is our own editorial caution.
Key figures at a glance
- Global fertility until 1965: about 5 children per woman
- Global fertility now: below 2.5 children per woman
- Peak global population growth: 2.3 percent a year in 1963
- Share of world population in countries below 3 children per woman: about 80 percent
- UN expectation for the end of the century: just below 2
Frequently asked questions
What is the global fertility rate?
Below 2.5 children per woman, according to Our World in Data, down from about 5 until 1965.
Which countries have the lowest fertility?
The article mentions Thailand at 1.3 and Taiwan close to 1 in the 2010s as examples.
Will fertility keep falling?
The UN expects it to be just below 2 children per woman by the end of the century.