Life Expectancy – 2025 Data, Calculator and Global Trends

Life expectancy is one of the most widely cited measures of population health, but it is also one of the most frequently misunderstood. It is not a prediction of how long any individual will live, nor is it a fixed biological limit. Instead, it is a statistical snapshot: the average number of additional years a person of a given age can expect to live, based on the death rates observed in a specific population during a specific period.

This figure changes over time and varies dramatically between countries, regions, and demographic groups. Understanding what life expectancy actually means, how it is calculated, and where the data comes from is essential for interpreting the numbers that appear in headlines and policy reports.

The following article draws on official data from the World Health Organization (WHO), the UK Office for National Statistics (ONS), the US Centers for Disease Control and Prevention (CDC), the World Bank, and academic sources such as Our World in Data to provide a clear, fact-based overview of life expectancy in 2025.

What Is Life Expectancy and How Is It Defined?

Life expectancy is the statistical estimate of the average number of additional years a person of a given age can expect to live, based on current age-specific death rates. The most common measure is life expectancy at birth, which reflects the overall mortality level of a population from birth through the entire life course.

Life expectancy is a hypothetical measure. It assumes that the age-specific death rates observed in a single year will apply throughout the lifetime of individuals born in that year. It is not a forecast of how long a newborn will actually live.

• Life expectancy has more than doubled globally in the last 200 years due to medical advances, sanitation, and nutrition.
• The UK life expectancy at birth is around 81 years (2023 ONS), with women living longer than men.
• Life expectancy varies by over 30 years between countries, reflecting disparities in healthcare, income, and environment.
• At age 65, life expectancy increases significantly – for example, a 65-year-old UK male can expect to live another 18–19 years.
• Down syndrome life expectancy has risen dramatically from 25 years in the 1980s to around 60 years today, thanks to better medical care.

Period vs. Cohort Life Expectancy

There are two main ways to calculate life expectancy. Period life expectancy uses the mortality rates observed in a single year and applies them to a hypothetical cohort. This is the metric used by the UN, WHO, and World Bank. Cohort life expectancy follows a real group of people born in a specific year, using observed data for the past and projected data for the future. For cohorts born between 1950 and 2000 in England and Wales, the gap between cohort and period life expectancy at birth has been around 8 to 10 years.

Healthy Life Expectancy

Another important concept is healthy life expectancy, which measures the average number of years a person is expected to live in good health or without disability. This figure is typically lower than total life expectancy, as it accounts for years lived with illness or injury.

What Is the Average Life Expectancy in the UK?

According to the ONS Life Expectancy Data, life expectancy at birth in the UK for 2022 to 2024 was 79.4 years for males and 83.1 years for females. These figures are based on period life tables and reflect mortality rates observed during that period.

The gap between male and female life expectancy in the UK has narrowed over recent decades, but women continue to live longer on average. At age 65, a UK male can expect to live another 18–19 years, while a UK female can expect another 20–21 years.

For the most recent ONS data, visit the ONS Life Expectancy Data page.

How Does Life Expectancy Vary by Country?

Life expectancy at birth ranges from approximately 33 years in the lowest-income nations to over 83 years in the most developed nations. The top 10 populations by life expectancy include Andorra (83.51), Macau, San Marino, Singapore, Hong Kong, Japan, Sweden, Switzerland, Australia, and Guernsey (UK).

The worst life expectancies are historically found in Africa, driven by lower economic development and high mortality from HIV/AIDS. The global average life expectancy at birth for 2024 is approximately 73 years, according to WHO and UN data.

Country-level differences are driven by income, healthcare access, sanitation, and lifestyle factors such as smoking and obesity. Within countries, disparities persist by income, region, and ethnicity. In the US, life expectancy varies by up to 20 years between the richest and poorest counties.

For a detailed comparison, the World Bank Life Expectancy Data provides interactive charts and country-level tables.

US Life Expectancy in Context

The US life expectancy at birth in 2023 was 79.0 years, according to the CDC. This places the US below many other high-income countries, despite high healthcare spending. The impact of COVID-19 caused temporary drops: US life expectancy fell to 76.1 in 2021, then recovered to 79.0 by 2023.

How Is Life Expectancy Calculated and Which Calculator Is Most Accurate?

Life expectancy is calculated using a life table, which incorporates data on age-specific death rates for the population in question. The process involves three main steps:

1. Data Collection: Requires enumeration data for the number of people and the number of deaths at each age, typically derived from national census and vital statistics.
2. Survival Probabilities: The life table shows the probability that a person will die before their next birthday for each age.
3. Mathematical Formula: Mathematically denoted as e_x (mean years of life remaining at age x), it is the arithmetic mean of the lifespans of all individuals in the population.

Major sources for national life tables include the United Nations Demographic Yearbook, WHO, CDC, and ONS. The standard demographic calculation relies on the life table method, not on individual health questionnaires.

The Our World in Data: Life Expectancy page provides an excellent long-form explanation of how life expectancy is calculated, including interactive charts and historical data.

What Is the Life Expectancy for Specific Demographics and Health Conditions?

Life expectancy varies significantly by sex, age, race, and geographic location. Globally, women tend to live longer than men. The average male life expectancy globally is several years lower than the female average, a pattern observed in nearly all countries.

At age 65, life expectancy increases significantly because the individual has already survived the higher mortality risks of infancy, childhood, and early adulthood. For example, a 65-year-old UK male can expect to live another 18–19 years, while a 65-year-old UK female can expect another 20–21 years.

Down Syndrome Life Expectancy

Life expectancy for individuals with Down syndrome has risen dramatically in recent decades. In the 1980s, it was around 25 years. Today, in developed countries, it has increased to approximately 60 years, thanks to better cardiac care and infection management.

Why Has Life Expectancy Increased Over Time?

The dramatic increase in global life expectancy since 1800 is primarily due to reductions in infectious disease, better nutrition, and safer childbirth. In 1800, global life expectancy was around 30 years. By 1900, it had risen to approximately 45 years, coinciding with the start of modern public health measures.

Post-war medical advances, including antibiotics, vaccines, and improved surgical techniques, drove further gains. By 1950, the global average had reached about 48 years. The significant reduction in child mortality throughout the 20th century was a major contributor.

By 2000, the global average had risen to approximately 65 years. The COVID-19 pandemic caused a temporary dip, with the global average falling to 71.4 years in 2021, but it has since recovered to around 73 years in 2024.

Historical Timeline of Global Life Expectancy

1. 1800: Global life expectancy ~30 years (Our World in Data)
2. 1900: Life expectancy ~45 years; start of modern public health
3. 1950: Global average ~48 years; post-war medical advances
4. 2000: Global average ~65 years; significant reduction in child mortality
5. 2021: Global average ~70 years; slight dip due to COVID-19
6. 2025: Projected global average ~73 years; continued gains in low-income regions

What Is Certain and What Remains Uncertain About Life Expectancy?

Past and current life expectancy figures from reputable sources such as the ONS, CDC, WHO, and World Bank are highly reliable. The global average for 2021–2024 is well-documented. However, projections into the future depend on assumptions about healthcare, pandemics, and climate change.

What Is the Broader Context of Life Expectancy Data?

Life expectancy is a summary measure of mortality across all ages and reflects overall population health. The dramatic increase since 1800 is primarily due to reductions in infectious disease, better nutrition, and safer childbirth. Country-level differences are driven by income, healthcare access, sanitation, and lifestyle factors such as smoking and obesity.

Within countries, disparities persist by income, region, and ethnicity. For example, in the US, life expectancy varies by up to 20 years between the richest and poorest counties. The impact of COVID-19 caused temporary drops, but most countries have seen recovery.

For further reading on related health topics, see What Is Long Covid and What Is NMN Supplement.

What Do Official Sources Say About Life Expectancy?

“Life expectancy at birth in the UK in 2022 to 2024 was 79.4 years for males and 83.1 years for females.”

— Office for National Statistics (ONS)

“Global life expectancy at birth increased from 66.8 years in 2000 to 73.3 years in 2019, but fell to 71.4 years in 2021 due to COVID-19.”

— World Health Organization (WHO)

“In 2021, the global average life expectancy was just over 70 years – an astonishing fact because just two hundred years ago, it was less than half.”

— Our World in Data

“Life expectancy at birth, United States: Both sexes 79.0 years; Males 76.5 years; Females 81.4 years (2023).”

— CDC National Center for Health Statistics

For the latest global data, visit the WHO Global Health Observatory and the CDC FastStats – Life Expectancy pages.

Summary: What Is the Key Takeaway About Life Expectancy?

Life expectancy is a powerful but often misunderstood statistic. It is not a personal prediction but a population-level snapshot based on current mortality rates. It has more than doubled globally in the last 200 years, driven by medical advances, sanitation, and nutrition. However, significant disparities remain between countries and within populations. Understanding the difference between period and cohort measures, and recognizing the limitations of projections, is essential for interpreting the data correctly. For more on related health topics, see What Is Long Covid.

Frequently Asked Questions About Life Expectancy