Life expectancy is an average, not a prediction for you

Life expectancy is the average number of years a person born in a given year is expected to live, based on death rates across an entire population. It is not a forecast of how long any individual will live. A life expectancy of 78 years means that if you gathered all people born in the same year and tracked them through their lives, the middle point would be around 78—some would die younger, some older.

Governments and health organizations calculate life expectancy using death records and population data. The United States Centers for Disease Control and Prevention (CDC) publishes life expectancy figures each year based on deaths recorded in the previous year. Other countries use similar methods through their national statistics offices.

Life expectancy varies by country, region, sex, and race because death rates differ across these groups. Understanding how the calculation works helps you see why these differences exist and what they do and do not tell you about individual lives.

Key Takeaways

  • Life expectancy is calculated by taking death rates at each age and computing the average age at death for an entire birth cohort, not a prediction for any one person.
  • The CDC publishes U.S. life expectancy annually using vital statistics data from death certificates filed in all states.
  • Life expectancy varies significantly by sex, race, and geography because death rates from specific causes differ across these groups.
  • A change in life expectancy of one year usually reflects shifts in deaths from a few major causes—often accidents, overdoses, or disease—not a change in how long most people live.

The basic calculation: working backward from death rates

Life expectancy starts with age-specific death rates—the number of deaths at each age divided by the number of people alive at that age in a given year. If 1,000 people aged 50 were alive in a year and 5 died, the death rate at age 50 is 5 per 1,000.

Statisticians then use these rates to build a life table, which shows how many people from a hypothetical group of 100,000 newborns would survive to each age, given the death rates observed that year. They start with 100,000 at birth and subtract deaths at each age based on the observed rates. By age 10, perhaps 99,500 remain. By age 50, perhaps 98,000. By age 100, perhaps 500.

Life expectancy at birth is the average age at which people in this hypothetical group would die. You add up all the years lived by all 100,000 people and divide by 100,000. That number is the life expectancy figure you see in news reports.

Life expectancy can also be calculated at any age—"life expectancy at age 65" tells you how many more years a 65-year-old is expected to live on average. This is useful for retirement planning because it accounts for the fact that people who reach 65 have already survived the higher death rates of childhood and young adulthood.

Why life expectancy changes year to year

Life expectancy does not change because people are living longer or shorter lives overall. It changes because death rates at specific ages shift. A one-year drop in U.S. life expectancy usually reflects a spike in deaths from one or two causes—often accidents, drug overdoses, suicide, or a particular disease outbreak.

For example, U.S. life expectancy fell from 2019 to 2020 and again from 2020 to 2021, largely because of deaths from COVID-19 and opioid overdoses. These deaths were concentrated in working-age adults, which pulled down the average more than deaths at older ages would have. If the same number of people had died at age 85 instead of age 45, the effect on life expectancy would have been much smaller.

Life expectancy also rises when death rates fall at younger ages. Improvements in infant mortality, childhood disease prevention, or accident reduction raise life expectancy more than similar improvements at older ages, because they affect more potential years of life.

How the CDC publishes U.S. life expectancy

The CDC's National Center for Health Statistics collects death certificate data from all 50 states, the District of Columbia, and U.S. territories. Each death certificate includes the person's age and the cause of death. The CDC uses this data to calculate age-specific death rates for the entire U.S. population and for subgroups by sex, race, and ethnicity.

The CDC publishes preliminary life expectancy figures about four months after the end of a calendar year. Final figures, which include late-filed death certificates, come out about 10 months later. These reports appear in the CDC's National Vital Statistics Reports series and are free to read from the CDC website.

The CDC also publishes life tables—the detailed year-by-year survival data—alongside the life expectancy figures. These tables show death rates and survival numbers at each age and are used by actuaries, demographers, and researchers.

Life expectancy by sex, race, and geography

Life expectancy in the United States varies by sex and race. Women have a higher life expectancy than men—typically about 5 to 6 years longer. This difference exists in nearly all countries and reflects higher male death rates at almost every age, particularly from accidents, suicide, and heart disease in working-age years.

Life expectancy also differs by race and ethnicity. These differences reflect unequal access to healthcare, differences in income and education, exposure to environmental hazards, and higher rates of certain diseases in some communities. The CDC publishes separate life expectancy figures for non-Hispanic White, non-Hispanic Black, Hispanic, non-Hispanic Asian, and American Indian and Alaska Native populations.

Within the United States, life expectancy varies by state and county. Some counties have life expectancies 15 to 20 years apart, driven by differences in poverty rates, healthcare access, smoking rates, and deaths from specific causes like overdoses or violence. The CDC's WONDER database allows you to look up life expectancy by county.

What life expectancy does not tell you

Life expectancy is an average, so it does not describe the typical person. If life expectancy is 78, it does not mean most people die at 78. Some die at 50, some at 95, and the average falls in the middle. A person who reaches age 65 has already beaten the average and can expect to live longer than the life expectancy at birth suggests.

Life expectancy also does not account for individual health, family history, lifestyle, or access to healthcare. Two people born the same year in the same place may have very different life spans based on whether they smoke, exercise, have health insurance, or have a family history of heart disease. Life expectancy describes the population, not the person.

Life expectancy figures are also always one year behind. The 2023 life expectancy figure, published in 2024, reflects deaths that occurred in 2023. It does not predict what will happen in 2024 or beyond.

Where to find life expectancy data

The CDC publishes U.S. life expectancy in the National Vital Statistics Reports series, available free on the CDC website under the National Center for Health Statistics section. These reports include life expectancy by age, sex, race, and ethnicity, plus detailed life tables.

The CDC's WONDER database (Wide-ranging Online Data for Epidemiologic Research) lets you search for life expectancy by state, county, year, age, sex, and race. You can also look up death rates by cause.

The World Health Organization (WHO) publishes global life expectancy figures by country in its World Health Statistics report each year. The United Nations also maintains life expectancy data by country in its demographic databases.

Academic researchers and demographers often use the Human Mortality Database, which holds detailed life tables and death rates for dozens of countries going back decades. This resource is free and useful if you want to compare life expectancy trends across countries or time periods.

Frequently Asked Questions

Does life expectancy mean most people die at that age?

No. Life expectancy is an average, not a typical age. If life expectancy is 78, some people die at 60 and some at 95. The average of all those deaths is 78. Most people do not die at the life expectancy age.

If I am 65, what is my life expectancy?

Life expectancy at age 65 is different from life expectancy at birth. A 65-year-old has already survived higher death rates in childhood and young adulthood, so they can expect to live longer than the life expectancy at birth suggests. The CDC publishes life expectancy at age 65 in its annual reports—it is typically around 19 to 20 additional years, meaning a 65-year-old can expect to reach about 84 or 85 on average.

Why did U.S. life expectancy drop recently?

U.S. life expectancy fell in 2020 and 2021 primarily because of deaths from COVID-19 and opioid overdoses. These deaths were concentrated in working-age adults, which pulled down the average more than deaths at older ages would have. Life expectancy can also fall if death rates rise from accidents, suicide, or disease at younger ages.

How do I find life expectancy for my state or county?

The CDC's WONDER database lets you search for life expectancy by state, county, year, age, sex, and race. You can access it free on the CDC website. The CDC also publishes state-level life expectancy in its annual National Vital Statistics Reports.

Is life expectancy the same as how long I will live?

No. Life expectancy is a population average based on death rates in a single year. Your actual lifespan depends on your individual health, family history, lifestyle, access to healthcare, and many other factors. Life expectancy describes the group, not the person.