TOP 10 Countries with Fastest Population Aging (2015–2025)
Between 2015 and 2025, the share of people aged 65 and over has risen at record speed in a handful of countries. This article uses United Nations population estimates to highlight the ten countries where ageing has accelerated most, explain why it is happening, and look ahead to what their societies may look like by 2050.
In this overview, “fast population ageing” means that the share of people aged 65+ grows quickly as a fraction of the total population. We track the change in percentage points (p.p.) between 2015 and 2025, using UN World Population Prospects estimates.
A rise of 5–8 p.p. in just one decade is extremely rapid: it means that one in five residents can move into the 65+ group in a single generation.
The fastest-ageing countries are concentrated in East Asia (such as South Korea, Singapore, China and Thailand), with additional leaders in Eastern Europe and several large upper-middle-income economies.
Most of them combine very low fertility with rising life expectancy and the “echo” of large mid-century birth cohorts moving into retirement age.
Table 1. Change in share of population aged 65+ (2015–2025), illustrative TOP 10
The table below summarises an illustrative set of ten countries where the share of people aged 65 and older has increased especially fast between 2015 and 2025. Values are rounded and based on UN population estimates for 2015 and 2025; the key metric is the absolute change in percentage points.
| Country | 65+ share 2015 (% of population) | 65+ share 2025 (% of population) |
|---|---|---|
| South Korea | ≈ 13 % | ≈ 21 % (+8 p.p.) |
| Singapore | ≈ 12 % | ≈ 19 % (+7 p.p.) |
| Thailand | ≈ 11 % | ≈ 17 % (+6 p.p.) |
| China | ≈ 10 % | ≈ 15 % (+5 p.p.) |
| Poland | ≈ 15 % | ≈ 19 % (+4 p.p.) |
| Viet Nam | ≈ 7 % | ≈ 11 % (+4 p.p.) |
| Turkey | ≈ 8 % | ≈ 12 % (+4 p.p.) |
| Brazil | ≈ 8 % | ≈ 11 % (+3 p.p.) |
| Russian Federation | ≈ 13 % | ≈ 16 % (+3 p.p.) |
| Iran (Islamic Republic of) | ≈ 6 % | ≈ 9 % (+3 p.p.) |
Note: Figures are rounded and indicative. They are based on UN World Population Prospects estimates for the period 2015–2025 and focus on the change in the percentage of the population aged 65 and over.
Line chart: growth of the 65+ population in selected leaders
This chart tracks the rise in the 65+ population share for five of the fastest-ageing countries over the decade, highlighting how quickly their age structure is shifting.
Bar chart: increase in 65+ share, 2015–2025 (Top 10)
The bar chart compares the absolute increase in the share of older persons (65+) for the same ten countries. It provides a visual “ranking” of population ageing speed.
Why are these countries ageing so quickly?
Population ageing is not driven by a single factor. Instead, it is the outcome of three long-term demographic forces that interact over decades:
- Falling fertility: Most of the countries in the Top 10 saw their fertility rates drop below the replacement level of about 2.1 births per woman many years ago. That means fewer young people are entering the population, while older cohorts continue to live longer.
- Rising life expectancy: Improvements in health care, living standards and education have steadily increased life expectancy. As more people live into their 70s and 80s, the 65+ group grows both in absolute numbers and as a share of the total population.
- Ageing of large birth cohorts: In countries such as China, Brazil or Poland, large generations born in the 1960s–1980s are now moving into retirement age. When a big cohort crosses the 65-year threshold, the curve of population ageing steepens.
Taken together, these trends mean that the age structure of these societies is changing much faster than in previous generations. Where it once took a century for some European countries to double their share of older persons, many East Asian economies are doing so in just 20–30 years.
From “ageing” to “super-aged” societies by 2050
The decade 2015–2025 is only the beginning. UN projections suggest that several of today’s fastest-ageing countries are likely to become “super-aged” societies by 2050, where more than 30% of the population is aged 65 and older. Even those that remain below this threshold will see a much older population structure than today.
The next table provides an indicative comparison between the estimated 65+ share in 2025 and the projected share in 2050 for the same ten countries, based on the UN medium-variant scenario.
Table 2. Projected share of population aged 65+ in 2050 for the same countries
By 2050, several of these countries are projected to have around one-third of their population aged 65 and older. That implies a very high old-age dependency ratio and significant pressure on labour markets, health systems and pension schemes.
| Country | 65+ share 2025 (% of population) | 65+ share 2050 (% of population, projection) |
|---|---|---|
| South Korea | ≈ 21 % | ≈ 38 % |
| Singapore | ≈ 19 % | ≈ 31 % |
| Thailand | ≈ 17 % | ≈ 30 % |
| China | ≈ 15 % | ≈ 30 % |
| Poland | ≈ 19 % | ≈ 30 % |
| Viet Nam | ≈ 11 % | ≈ 23 % |
| Turkey | ≈ 12 % | ≈ 22 % |
| Brazil | ≈ 11 % | ≈ 24 % |
| Russian Federation | ≈ 16 % | ≈ 27 % |
| Iran | ≈ 9 % | ≈ 20 % |
Projections are based on the UN medium-variant scenario for 2050. They assume that fertility, mortality and migration follow trajectories consistent with recent trends and expert assessment.
Economic and social implications
Fast population ageing reshapes almost every dimension of the economy and social policy. A higher share of older people means a rising old-age dependency ratio: fewer workers are available to support more retirees through pay-as-you-go pension systems and tax-financed public services.
Labour markets may face slower growth in the working-age population, or even an outright decline. That puts a premium on productivity-enhancing policies, from digitalisation and innovation to investment in skills and lifelong learning.
At the same time, demand for health and long-term care services rises sharply as more people live into their 80s and 90s. Countries that age fastest must scale up geriatric care, rehabilitative services and age-friendly housing more quickly than others.
Pressure on pensions and public finance
In most of the Top 10, population ageing coincides with still-developing pension systems. Rapid growth in the 65+ population can therefore create fiscal stress if benefit rules are not adjusted. Governments may need to:
- Gradually raise statutory and effective retirement ages.
- Encourage higher labour-force participation of older workers.
- Diversify retirement income through a mix of public, occupational and private pension pillars.
Where reforms are delayed, the combination of fewer workers and more retirees can translate into higher contribution rates, lower benefits, or both.
Health, inequality and quality of ageing
Ageing itself is not a crisis. The real challenge is whether additional years of life are lived in good health and with adequate income. In countries that are ageing quickly but still have relatively low income levels, there is a risk that older adults face:
- Limited access to preventive and long-term health care services.
- Insufficient pension coverage, especially for informal-sector workers.
- Higher poverty risk for women, who often have interrupted careers.
Addressing these gaps requires a life-course approach: investing in health, education and decent work well before people reach retirement age, so that they can age in better physical, mental and financial condition.
Policy priorities for fast-ageing countries
While each country’s context is different, the policy toolbox for managing rapid ageing has several common elements:
- Active ageing policies: promoting longer, healthier working lives and removing barriers to employment for older people.
- Age-friendly cities and infrastructure: adapting transport, housing and public spaces to the needs of older residents.
- Support for families and caregivers: expanding community-based services, respite care and financial support for family carers.
- Migrant labour and integration: in some cases, carefully managed migration can partially offset workforce decline, but it is not a substitute for structural reforms.
The countries in this Top 10 are effectively “early warning systems” for the rest of the world: the policies they test in the 2020s and 2030s will inform how other regions respond as their own populations age.
Global context: ageing is accelerating everywhere
Although this article focuses on ten particularly fast-ageing countries, it is important to keep the global picture in mind. UN projections show that the worldwide share of people aged 65 and over is on track to roughly double between 2020 and mid-century, rising from around one in ten to nearly one in five people on the planet.
The speed of this transition is unprecedented. Unlike past demographic shifts, it is occurring in low- and middle-income countries that have less time to build comprehensive social protection systems before becoming older societies. Designing policies that support healthy, productive and dignified ageing is therefore one of the central public-policy challenges of the twenty-first century.
The experience of South Korea, Singapore, Thailand, China, Brazil and the other countries highlighted here underlines a simple message: demography is not destiny. The way societies prepare for and respond to population ageing will determine whether longer lives become a strain on social contracts or a success story of human development.
Primary data sources and further reading
The figures and rankings in this article are illustrative and based on the latest available releases of UN and World Bank demographic datasets. For exact, up-to-date values and official country tables, readers should work directly with the following sources:
-
United Nations – World Population Prospects (Online Edition).
Age-structured population estimates and projections by country from 1950 to 2100, including the share of people aged 65+ used to construct the 2015–2025 changes and 2050 projections.
https://population.un.org/wpp -
World Bank – “Population ages 65 and above (% of total population)”, indicator SP.POP.65UP.TO.ZS.
Annual time-series share of 65+ in total population by country, derived from UN Population Division data and updated on a regular basis.
https://data.worldbank.org/indicator/SP.POP.65UP.TO.ZS -
UN and UNFPA thematic material on population ageing.
Narrative overviews, policy briefs and global factsheets on the scale and speed of ageing, the concept of “super-aged” societies and the implications for social protection and health systems.
https://www.un.org/en/global-issues/ageing
https://www.unfpa.org/ageing -
WHO – Ageing and health.
Background on healthy ageing, functional ability in older age, and health-system reforms needed as the share of older persons rises, particularly in low- and middle-income countries.
https://www.who.int/news-room/fact-sheets/detail/ageing-and-health
When reproducing or extending the charts and tables, always verify that you are using the most recent revision of the UN and World Bank datasets, and document the exact vintage of the data in your notes or metadata.
Download assets: TOP 10 countries with fastest population ageing
ZIP archive with the data table (CSV) and chart images for the article on the fastest-ageing countries (2015–2025). Suitable for reuse in your own analysis, dashboards or publications with a link to StatRanker.org.
Contents: 1 CSV file with country data (65+ share 2015–2050, illustrative) and 2 PNG charts (line chart and bar chart) in ready-to-use resolution.
