Total fertility rate

The total fertility rate (TFR) tells us how many children a woman might have on average during her whole life, if the number of babies born at each age stays the same as it is today. It helps us understand how families and populations change over time.

In 2023, the TFR was very different in different places. For example, it was just 0.7 in South Korea, meaning that, on average, women were having fewer than one child each. But in Niger, it was 6.1, meaning families were much larger. Some bigger countries, like China and South Korea, had a TFR of 1.0 or lower, which means they were having fewer babies than needed to replace each generation.

Fertility rates are often lower in places with more money, better education, and more cities. In these areas, people usually have fewer children. In places with less money and fewer schools, families often have more children because they help with work and care for older parents. Also, not everyone has easy access to ways to prevent pregnancies, which can affect how many children families have.

Before the 1800s, most places had TFRs between 4.5 and 7.5. That means families were much bigger long ago. Since then, the number of children per woman has gone down a lot. By 2023, the world average was only 2.3 births per woman. The United Nations thinks this number will keep falling and might drop to 1.8 by the year 2100. They also think the total number of people in the world will stop growing around the year 2084.

How TFR is actually computed

The total fertility rate (TFR) for a year, like 2024, is found using a special math formula. It shows the average number of children a woman might have during her life if the current birth rates stay the same.

Usually, people use a simpler formula that looks at groups of women aged 15 to 49. This is easier because it uses data from five-year age groups. But the perfect way would be to use a more detailed formula that looks at each single year of age. However, that detailed data isn’t always available, so the simpler method is used most often by governments and international groups.

Related metrics

Net reproduction rate

Another way to measure fertility is called the net reproduction rate (NRR). This tells us how many daughters a girl might have in her lifetime if she faced today’s birth and death rates. When the NRR is exactly 1, each generation of girls replaces itself perfectly.

Total period fertility rate

The total fertility rate (TFR), also known as the total period fertility rate, is a good way to show current fertility levels. It is better than just looking at the number of births each year because it does not depend on the ages of women in the population. However, it does not always predict exactly how many children young women will have later in life, since their choices might change.

Tempo effect

Further information: Sub-replacement fertility § Tempo effect

The total period fertility rate can be affected by when women choose to have children. If women start having children later in life, the TFR might look lower for a while, even if the total number of children they plan to have stays the same. Once women stop delaying childbirth, the TFR may go up again, even though the total number of children each woman has hasn’t changed. This timing effect can make the TFR tricky to use in some countries where the age of having children changes over time, like the Czech Republic and Spain in the 1990s.

Replacement rates

Further information: Sub-replacement fertility

Replacement fertility is the number of children women need to have to keep the population stable, assuming death rates stay the same and no people move in or out of the country. If this level of fertility continues for a long time, each generation will replace itself perfectly. In 2003, most developed countries needed about 2.1 births per woman, but in some less developed countries, it could be as high as 3.5 because more children might not survive to grow up. From 2010 to 2015, the global average needed to keep the world population stable was about 2.3 children per woman.

Lowest-low fertility

The term lowest-low fertility means a total fertility rate (TFR) of 1.3 or fewer children per woman. This idea became popular in research in 2002.

At first, lowest-low fertility was seen mostly in East Asian and European countries. Later, it spread to the Americas. The lowest rates are still in East Asia, including the East Asian American community in the United States. In recent years, fertility rates have been falling again. For example, in 2023, Spain’s rate dropped to 1.19 and Italy’s to 1.2. In Canada, the rate in 2023 was 1.26, the lowest ever recorded.

The world’s lowest TFR ever recorded was in the Xiangyang district of Jiamusi city in Heilongjiang, China, with just 0.41 children per woman in 2000. In 2023, South Korea had the world’s lowest rate at 0.72, which rose to 0.8 by 2025. In 2025, Taiwan had the lowest rate of any country, at 0.695.

Population-lag effect

If a group of people keeps having about 3.8 children for each woman over many years, and not many people die or leave, the group will grow very fast. It could double in size in about 32 years. But if the group only has about 2.0 children for each woman for a long time, the group will get smaller unless many new people move in.

It can take many years for changes in how many children families have to show up in the number of babies born each year. This is because it depends on the ages of the people having children. For example, even if a group starts having fewer children than before, it might still grow for a while because many young couples are now old enough to have children.

This slow change over many years is called population momentum or the population-lag effect. It is very important for understanding how fast groups of people grow or shrink over time.

Influencing factors

Main article: Fertility factor (demography)

Further information: Population decline and Sub-replacement fertility

Since the mid-20th-century baby boom that followed the end of World War II, declining fertility rates have been seen in many modern industrialized, affluent societies. Places with the biggest drops in population include Western Europe, Japan, the Russian Federation, and South Korea. Other areas, like the United Kingdom, the United States, and parts of developing, poorer regions of the world, such as the Balkans, Central Asia, the Middle East, and Sub-Saharan Africa, are also feeling these changes.

What affects how many children families have includes things like economic inequality, jobs that stay steady, wealth disparities, how important people think religiosity is, social media, social class, having affordable housing, pension plans, and worries about having too many people, or overpopulation. For example, Nordic countries and France don’t usually focus much on religiosity but have more children, while places like Cyprus, Greece, Poland, Portugal, and Spain are different. One important idea about development and family size was shared by Karan Singh at the 1974 United Nations world population conference in Bucharest. He said that helping people improve their lives is the best way to help families decide to have fewer children.

National efforts to increase or decrease fertility

Governments sometimes try to change how many children families have, either by encouraging more or fewer births. Some past policies were very strict and unfair. For example, in Romania from 1967 to 1989, laws made it hard for women to prevent pregnancies, and many families struggled to care for their children.

Other countries, like China, tried to reduce family sizes with rules limiting how many children a family could have. These efforts sometimes led to unfair treatments. Today, many believe that people should have the freedom to choose how many children to have without pressure from the government. This idea is known as reproductive rights, which means everyone should be able to make their own decisions about having children safely and fairly.

History and future projections

From around 10,000 BC to the start of the Industrial Revolution, families around the world usually had many children, often between 4 and 7 for each mother. This was because many children did not live to grow up, and families needed more kids to ensure some would survive and help later in life.

The Industrial Revolution, which began around 1800, changed this pattern. As places like Great Britain, Europe, and the United States improved health and food, fewer children died. With better public sanitation, personal hygiene, and food supply, families did not need to have as many children. This led to a slow decrease in the number of children families had over time.

For example, in the United States in 1800, about one-third of children died before turning five, and mothers had on average seven children. By 1900, fewer children died, and the average dropped to about four children. By 1950, even fewer children died, and the average was down to about three children. Today, the average number of children a mother has worldwide is just above the level needed to keep populations stable.

The number of children families have continues to fall, and experts think it may drop even more in the future. Some countries, like Thailand and Chile, are seeing very low numbers of children being born, which could affect how societies grow and age in the years to come.

By region

Main article: List of countries by total fertility rate

The United Nations groups the world into six areas. The table below shows the average number of children born to a woman in each area.

In 2013, the number of children born to women in Europe, Latin America and the Caribbean, and Northern America was less than the world average of 2.1 children.

Africa

Africa has the highest average number of children born to a woman in the world, at 4.1. Angola, Benin, DR Congo, Mali, and Niger have the highest numbers. In 2023, Nigeria, the most crowded country in Africa, had about 4.57 children born per woman. In 2023, Ethiopia, the second most crowded, had about 3.92 children per woman.

Asia

Eastern Asia

Hong Kong, Macau, Singapore, South Korea, and Taiwan have the lowest numbers of children born to women in the world. In 2004, Macau had fewer than 1 child born per woman. In 2018, North Korea had the highest number in East Asia, at 1.95.

China

Further information: Aging of China

In 2022, China had 1.09 children born per woman. China started a rule in 1979 to limit most families to one child. In 2016, this changed to allow two children. In 2021, a rule allowing three children was added because China’s population is growing older faster than almost any other country.

Japan

Further information: Aging of Japan

In 2022, Japan had 1.26 children born per woman. Japan’s population is growing older quickly because people live longer and fewer babies are born. The total number of people is getting smaller. Hong Kong and Singapore balance this with immigrant workers. Japan has fewer immigrants to Japan.

South Korea

Further information: Aging of South Korea

In South Korea, having few babies is a big problem. High housing costs, fewer jobs for young people, and not enough help for families with babies are reasons why the number of babies is so low. In 2019, the number of babies born per woman was 0.92. South Korea has tried many ideas to help families have more babies, but it is still very hard. In 2022, South Korea had the lowest number of babies born per woman in the world, at 0.78. In the capital, Seoul, the number was even lower, at 0.57.

Southern Asia

Bangladesh

The number of children born to a woman fell from 6.8 in 1970–1975 to 2.0 in 2020.

India

The number of children born to a woman in India has gone down a lot. In 1971, it was 5.2. In 2018, it was 2.2. In 2019–2020, it went below 2.0 for the first time. In 2026, it is expected to be about 1.9.

Iran

In 2019–2020, Iran had 1.8 children born per woman.

Western Asia

In 2023, Turkey had 1.51 children born per woman.

Europe

Main article: Ageing of Europe

See also: Aging of Russia

In 2021, the European Union had 1.53 children born per woman. In 2021, France had the most at 1.84, followed by Czechia (1.83), Romania (1.81), Ireland (1.78), and Denmark (1.72). Malta had the fewest at 1.13. Other southern European countries also had low numbers (Portugal 1.35, Cyprus 1.39, Greece 1.43, Spain 1.19, and Italy 1.25).

In 2021, the United Kingdom had 1.53 children per woman. In 2021, Russia had 1.60, Moldova 1.59, Ukraine 1.57, and Belarus 1.52.

Latin America and the Caribbean

In 2023, Brazil, the biggest country in the area, had 1.75 children per woman. In 2021, Mexico had 1.73. The next four biggest countries had between 1.9 and 2.2 children per woman in 2023: Colombia (1.94), Argentina (2.17), Peru (2.18), and Venezuela (2.20). Belize had the most at 2.59 in 2023. In 2021, Puerto Rico had the fewest at 1.25.

Northern America

Canada

Main article: Aging of Canada

In 2023, Canada had 1.26 children per woman.

United States

Further information: Aging of the United States

After staying the same for thirty years, the number of babies born went down again in 2008.

The number of children born to a woman in the U.S. has been going down and is now less than the number needed to keep the population the same. After World War II, the number was about 3.8 in the late 1950s. It went below the replacement number in the early 1970s and to 2 in 1999. Now, it is below the replacement number for people born in the U.S., but higher for families who move to the U.S. from other countries. However, the number of children in these families goes down quickly in the next generation, as they get more education and money. In 2021, the U.S. had 1.664 children per woman, with some states over 2 and others under 1.6.

Oceania

Australia

Further information: Ageing of Australia

After World War II, Australia had about 3.0 children per woman. In 2017, Australia had 1.74, which is less than the number needed to keep the population the same.