Life Expectancy Estimator

The Life Expectancy Estimator gives you a statistical estimate of your lifespan from your date of birth, gender and a few lifestyle factors.

It starts from a United Nations World Population Prospects 2024 baseline for the country, sex and age you enter, and adjusts that baseline up or down with the lifestyle values in the table below.

The result reflects population averages, not your personal future. Use it as context for long-term planning and for thinking about healthy habits. This tool provides a statistical estimate for information only. It is not a medical prediction, and it does not replace advice from a qualified health professional.

One thing the old guide got wrong needs stating first, because it changes how to read everything below. The old guide said the calculator starts from one fixed baseline, 79 years for men and 84 for women, whatever country you pick.

That is not what the tool does. The tool starts from United Nations World Population Prospects 2024 baselines for the country and sex you pick, at your current age. For a man of 36, the tool states 79.1 years for the United States and 83 years for Japan.

The country you pick changes the estimate: the same answers give 84 years for the United States and 87 years for Japan. The Social Security table in this guide is still a reference table, built by hand; the tool reads the UN tables, not the Social Security table.

How the Estimate Works

Enter your birth date as month, day and year, or tap the “Show date picker” link to open the native picker. Then pick your country, your gender, and five lifestyle choices: smoking, exercise, diet, sleep and alcohol. Three quick chips sit below the form.

The first is a US man born 14 May 1990 with healthy habits, the second the same man as a smoker, and the third a UK woman born 8 March 1986 with healthy habits. Each one calculates at once.

With no birth date entered, the calculator answers: “Please enter your date of birth.” A calendar date that never happened, 31 February for example, is refused with: “That date is not valid. Please use a 4-digit year.” A birth date after today is answered with: “Your date of birth cannot be in the future.”

The result is a big line reading “84 years”, a line reading “You are 36 years old.”, a line reading “About 47 years remaining.”, and a line reading “Projected: 7 December 2073.” Three stats sit underneath: the lifespan, the remaining years and the projected year.

The projected date follows the remaining years. For the United States man above it reads 7 December 2073, and for the same man in Japan it reads 27 October 2077. When the remaining years are zero or below, the tool says “You have already reached your estimated life expectancy.” and the remaining-years stat reads 0.

A 29 February birth date is clamped to 28 February when the target year is not a leap year.

Worked example: a 36-year-old man in the United States, born 14 May 1990. The tool’s United Nations baseline for a man of 36 in the United States is 79.1 years. He does not smoke (+0), exercises regularly (+3), eats a healthy diet (+2), sleeps well (+0), drinks moderately (+0).

Adjusted estimate: 79.1 + 3 + 2 = 84.1 years, shown as 84 years. If the same man smoked a pack a day (-7) and was sedentary (+0 exercise): 79.1 – 7 = 72.1 years, shown as 72 years. That is a 12-year gap from lifestyle alone.

Change only the country to Japan and the same answers give 87 years, 3 years above the United States result. The tool states the United Nations baseline for a man of 36 in Japan as 83 years, against 79.1 years for the United States.

A former smoker with the same healthy habits gets -2 + 3 + 2 = +3, or 79.1 + 3 = 82.1 years, shown as 82 years. The most the adjustments can add is +5, so the highest estimate is the United Nations baseline plus 5: 84 years for the United States man above.

The most they can take away is -13, current smoking, a poor diet, chronic poor sleep and heavy alcohol together, for 66 years for the United States man above: 79.1 – 13 = 66.1 years, shown as 66.

Lifestyle Factor Impact

Each factor below shows the approximate years added or subtracted from your baseline. These are population-level averages from peer-reviewed research, not guarantees for any individual.

The values are the tool’s own values, added at full strength: the tool does not dampen the combined effect when several risk factors stack, which is one way it differs from the calculators in the comparison table below.

The Same 36-Year-Old, Three Lifestyles

How one profile’s estimate changes across three sets of habits, which shows what the inputs actually do. The profile is the United States man born 14 May 1990 above, aged 36, and the baseline is the tool’s United Nations figure for him, 79.1 years. Every adjustment comes from Table 1.

The old version of this table used a different baseline and adjustments that Table 1 does not contain; the table below is the tool’s own arithmetic.

These are illustrative population figures, not predictions about any one person. Diabetes is not one of the tool’s inputs, so it does not appear in this table: the old version listed a diabetic smoker, which the tool cannot model. The years remaining are for a man aged 36.

What a Real Life Table Says

The tool’s baseline is a life-table value: the United Nations figure for your age, sex and country. It is still a rough average, not a personal figure. A real life table gives a different number at every age, because the older you are today, the more years you have already survived.

The table below is from the U.S. Social Security Administration’s 2023 period life table, the same table actuaries publish. Remaining years are the average years left for a person at that exact age; expected age is the current age plus the remaining years.

Two things to take from the table. First, the expected age rises as you get older: a man born today can expect 75.8 years, a 50-year-old man 79.9, and an 80-year-old man 88.5, because the 80-year-old has already survived the risks of the years behind him.

The tool does do this: its baseline is the United Nations expected age at your current age, so it rises as you get older, just as the Social Security figures rise here.

Second, the gap between men and women narrows with age: 5.3 years at birth, 3.6 years at 50, 1.3 years at 80. The gap in the tool’s United Nations baselines varies by country and age; it is not a fixed 5 years.

The life-table number comes from a simple formula. Remaining life expectancy at age x, written e_x, equals T_x divided by l_x: the total person-years lived beyond age x, divided by the number of survivors at age x.

The Social Security table publishes both figures for every age from 0 to 119.

The formula describes a life table, and the tool’s United Nations baseline comes from one. The tool starts from the United Nations expected age at your current age, then adds and subtracts the Table 1 values. The Social Security table itself is a reference table; the tool reads the United Nations tables.

Life Expectancy by Country

The country you pick in the tool changes the estimate. The differences between countries are large, and they are worth seeing. The table below is life expectancy at birth for 2026, from the UN World Population Prospects 2024 revision. A dash means the sex split was not in the source used.

The gap between the longest-lived and shortest-lived countries is more than 30 years: a child born in Monaco can expect 86.7 years, a child born in Nigeria 55.0. The United States, at 79.8, sits below Canada at 83.1 and the United Kingdom at 81.7, and below every country in the top ten.

These are period figures: the average years a newborn would live if that year’s age-specific death rates held for life. They are not forecasts for one individual, and they are figures at birth, while the tool uses the figure at your current age.

What the Tool Does Not Ask

The tool asks for five lifestyle factors: smoking, exercise, diet, sleep and alcohol. Rival calculators ask for more. HealthCalculatorOnline asks for ten, including blood pressure, body weight, stress, family history and diabetes.

None of those five are inputs here, so a person with high blood pressure or a family history of early heart disease gets the same estimate as a person without them, if the five inputs match.

That is a real limit, and it is one reason the result is a rough average rather than a personal figure. The tool also gives no chance of reaching 80, 90 or 100, and no range around the single number.

Kuakua gives both, with a range of about plus or minus 3 years for a neutral profile and up to plus or minus 12 when risk factors accumulate. Moneydeck gives the chances of reaching 80, 90 and 100, which were 57 percent, 28 percent and 5.5 percent for its default 40-year-old man.

Methodology and limitations

This estimator starts from United Nations World Population Prospects 2024 baselines for the country and sex chosen, at your current age, adjusted by the lifestyle factors in Table 1, which are drawn from large peer-reviewed cohort studies.

It does not account for genetics, pre-existing conditions, accidents, or medical advances. The result is a statistical estimate, not a prediction. This article is for information only and is not medical advice. Consult a healthcare professional for personal health guidance.

How This Calculator Compares

Three life expectancy calculators rank for the same query, and each one models the same question differently. The table below sets them side by side so you can compare the methods.

Where this estimator stops: it has no BMI, blood pressure, stress, family history or diabetes input, it gives no chance of reaching 80, 90 or 100, and it gives no range. Moneydeck gives the chances; HealthCalculatorOnline gives the range and the score; Kuakua gives the range and the chances.

What this page gives that none of the three does is the projected date and the Social Security reference table by age and sex, worked by hand in the guide.

Keep Exploring

Retirement Age Calculator: see the age you can retire at, with the 62, 67 and 70 claiming ages worked through on a real benefit figure.

Half Birthday Calculator: find the date six months after any birthday, with its weekday, and the table that shows which summer birthdays gain a school session.

Days Lived Calculator: count the days you have lived from any birth date, with the 1,000-day milestones and the live ticking hours, minutes and seconds.

Life in Weeks: see your whole life as a grid of weeks, with the four seasons of life and the weeks still ahead.

Sources

U.S. Social Security Administration: Actuarial Life Table (the 2023 period life table for the Social Security area population, remaining years by exact age and sex)

World Health Organization Global Health Observatory, via Our World in Data: Life Expectancy at Birth (life expectancy at birth by country, from the World Health Organization Global Health Observatory)

World Population Review: Life Expectancy by Country (life expectancy at birth by country for 2026, from the UN World Population Prospects 2024 revision)

Frequently Asked Questions