World population ageing: why over-65s will soon outnumber children
The world is getting older because people are having fewer children and living longer. The UN projects that people aged 65 and over will outnumber children under 18 by the late 2070s, with Japan, Europe and China already feeling the effects.
The world's population is ageing because fertility has fallen sharply while life expectancy keeps rising. According to the United Nations, people aged 65 and over will outnumber children under 18 by the late 2070s, and people aged 80 and over will outnumber infants by the mid-2030s. In some countries, the shift is already visible in shrinking workforces and rising pension bills.
How fast is the world's population ageing?
The number of older people is rising quickly in absolute terms. The World Health Organization says there were 1 billion people aged 60 or over in 2020, a number expected to reach 1.4 billion in 2030 and 2.1 billion in 2050. By 2050, the number of people aged 80 or over is projected to reach 426 million, according to the WHO's ageing and health fact sheet.
The UN's World Population Prospects 2024 adds two milestones. By the mid-2030s, people aged 80 and over are projected to outnumber infants. By the late 2070s, people aged 65 and over are projected to outnumber children under 18. The UN also expects that by the late 2050s, more than half of all deaths worldwide will occur at age 80 or older.
Why is the world getting older?
Two forces drive ageing: fewer births and longer lives. The UN reports that in more than half of all countries and areas, women now have fewer than 2.1 children on average, the level needed to keep a population stable without migration. In nearly a fifth of countries, fertility is "ultra-low", below 1.4 children per woman. Globally, women have one child fewer on average than they did around 1990.
At the same time, global life expectancy reached 73.3 years in 2024, up from 70.9 years during the pandemic, according to the same UN report. Fewer children and more survivors into old age push up the average age of the whole population. As a result, the UN expects the world's population to peak at around 10.3 billion in the mid-2080s, then slip to about 10.2 billion by 2100.
Which countries are the oldest?
Japan is the oldest large country in the world. The Japanese government estimated that 29.6% of the population was aged 65 or over in September 2026, a record and the highest share among countries of more than 40 million people, Kyodo reported. Italy and Germany followed.
| Country or region | Aged 65 and over | Date | Source |
|---|---|---|---|
| Japan | 29.6% | September 2026 | Ministry of Internal Affairs, via Kyodo |
| Italy | 25.6% | 2026 | Ministry of Internal Affairs, via Kyodo |
| Germany | 24.2% | 2026 | Ministry of Internal Affairs, via Kyodo |
| European Union | 22.0% | 1 January 2025 | Eurostat |
In the European Union, the median age reached 44.9 years on 1 January 2025, according to Eurostat. China is ageing from a lower base but very quickly. Its population fell by 3.39 million in 2025 to 1.405 billion, the fourth annual decline in a row, as births dropped to 7.92 million and deaths rose to 11.31 million, Reuters reported from official data.
What does an ageing population mean for the economy?
The main economic effect is that fewer workers support more retirees. In the EU, the old-age dependency ratio was 34.5% on 1 January 2025, meaning just over three people of working age for every person aged 65 or over, Eurostat says. Eurostat also projects that the share of people aged 80 or over in the EU will rise from 6.2% in 2025 to 15.3% in 2100.
Governments are responding in several ways:
- Later retirement. China began raising its statutory retirement age on 1 January 2025, the first increase in decades. Over 15 years, the age for men rises from 60 to 63, and for women from 50 to 55 or from 55 to 58 depending on the job, Euronews reported.
- Policies to support families. Tokyo's metropolitan government introduced an optional four-day week for its staff in 2025, explicitly to help young families; we look at the wider evidence in our explainer on four-day week trials.
- Health and care spending. More people living into their 80s means more demand for long-term care and for treatment of age-related conditions, including memory loss, which we cover in how memories last.
Is the whole world ageing at the same pace?
No. Ageing is uneven, and many countries are still young and growing. The UN counts 63 countries and areas whose populations had already peaked by 2024; together their population is projected to shrink by 14% over the next 30 years. Another 48 countries, including Brazil, Iran, Türkiye and Viet Nam, are expected to peak between 2025 and 2054.
In the remaining 126 countries, populations are projected to keep growing through 2054, and in nine of them the population is expected to double between 2024 and 2054. Even so, the WHO expects most older people to live in low- and middle-income countries by 2050, which means ageing will increasingly be a challenge for countries with smaller pension and health systems.
Frequently asked questions
When will the world's population peak?
The United Nations' World Population Prospects 2024 projects that the world's population will peak in the mid-2080s at around 10.3 billion people, up from 8.2 billion in 2024. It is then expected to decline slightly to about 10.2 billion by the end of the century. The UN says this is about 700 million fewer people in 2100 than it anticipated a decade ago.
Which country has the oldest population?
Among large countries, Japan has the oldest population. In September 2026, Japan's government estimated that 29.6% of its population was aged 65 or over, a record high. That is the highest share among the 39 countries with populations of 40 million or more, ahead of Italy at 25.6% and Germany at 24.2%.
What fertility rate keeps a population stable?
Demographers use a fertility rate of about 2.1 children per woman as the replacement level, the rate at which a population stays stable in the long run without migration. The UN reports that fertility is now below 2.1 in more than half of all countries and areas, and below 1.4 in nearly a fifth of them.
What is the old-age dependency ratio?
The old-age dependency ratio compares the number of people aged 65 and over with the number of people of working age, usually 15 to 64. A higher ratio means fewer workers for each older person. In the EU, the ratio was 34.5% on 1 January 2025, or just over three working-age people for every person aged 65 or over.
Is China's population shrinking?
Yes. China's population fell for the fourth consecutive year in 2025, by 3.39 million to 1.405 billion, according to official data reported by Reuters in January 2026. Births fell to 7.92 million from 9.54 million in 2024, while deaths rose to 11.31 million. China has also started gradually raising its retirement age.
Sources
- United Nations — UN projects world population to peak within this century (World Population Prospects 2024) (11 July 2024)
- World Health Organization — Ageing and health fact sheet (1 October 2025)
- Eurostat — Population structure and ageing (data extracted 2 February 2026)
- The Star / Kyodo — Japan's elderly population hits a record 29.6 per cent (20 September 2026)
- NBC News / Reuters — China's population falls for a fourth straight year (18 January 2026)
- Euronews — China raises its retirement age as older population threatens economy (13 September 2024)
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