Life expectancy is the average number of years people of a given age would live if today’s death rates stayed the same for the rest of their lives. In the Social Security Administration’s 2023 US period life table, it’s 75.79 years at birth for males and 81.06 for females; at age 65 it’s another 18.12 and 20.66 years.
Those two kinds of figure, life expectancy at birth and the years remaining at your current age, answer different questions, and mixing them up is the most common mistake people make with the numbers. This guide explains both, how a period life table is built, why every figure is an average rather than a forecast, and exactly what our life expectancy calculator can and can’t tell you.
Life expectancy at birth vs. at your age
Life expectancy at birth is the average lifespan for a group of newborns, assuming the death rates of one year apply to them at every age. It’s the headline number in news stories and country comparisons.
Remaining life expectancy is the average number of further years for people who have already reached a given age. It’s the figure that matters once you’re an adult, and it’s the one our life expectancy estimate starts from.
The two don’t simply subtract. A 65-year-old man doesn’t have 75.79 − 65 = 10.79 years left on average; the table gives 18.12. The reason is survival: everyone who reaches 65 has already lived through childhood and middle age, so the deaths that pull the at-birth average down are behind them. The older you get, the later your expected age at death.
What the US period life table shows
Here are selected rows from the SSA period life table for 2023, as used in the 2026 Trustees Report. The last two columns add each age to its remaining years.
| Exact age | Male: years left | Female: years left | Male: average age reached | Female: average age reached |
|---|---|---|---|---|
| 0 | 75.79 | 81.06 | 75.8 | 81.1 |
| 20 | 56.69 | 61.74 | 76.7 | 81.7 |
| 40 | 38.59 | 42.64 | 78.6 | 82.6 |
| 60 | 21.79 | 24.73 | 81.8 | 84.7 |
| 65 | 18.12 | 20.66 | 83.1 | 85.7 |
| 80 | 8.50 | 9.82 | 88.5 | 89.8 |
| 90 | 4.11 | 4.80 | 94.1 | 94.8 |
The “average age reached” column climbs with every row, which is the survival effect in numbers. SSA publishes a new table each year with the Trustees Report, and its actuarial life table page moves on to the newest one. Earlier editions stay online at their own addresses, such as the 2021 table from the 2024 Trustees Report, which gave 73.54 years at birth for males and 79.30 for females.
Period vs. cohort life tables
SSA describes period life expectancy at a given age as the average remaining years for a person at that exact age, using that year’s death rates for the rest of their life. In other words, a period table is a snapshot: it takes the death rates observed at every age in one calendar year and asks what would happen to a group who lived their whole lives under those rates.
No real group does. Someone who is 40 today will be 80 decades from now, when death rates at 80 may be different. A cohort life table follows people born in the same year through their actual or projected lives instead, which means it has to forecast future death rates. Period tables avoid that guesswork, which is why they’re the standard way to report life expectancy, but it also means they describe the present, not the future.
A period figure can also move with one unusual year. The 2023 table reflects death rates in 2023 only, so tables for different years can differ noticeably: at birth, the 2021 table was 2.25 years lower for males and 1.76 years lower for females.
How our life expectancy calculator works
The life expectancy quiz asks ten questions: your date of birth, your sex (female, male, or “prefer not to say”) and eight everyday habits. It then:
- reads the average years remaining at your age from the 2023 US period life table, using values at ages 0, 10, 20 and so on up to 100, joined by straight lines in between; “prefer not to say” uses the average of the female and male tables;
- adds or subtracts the effect of each habit, as reported by a large published study;
- keeps the result at one year or more, and turns it into weeks and an estimated date counted from today.
Where a study reports a hazard ratio, the tool converts it to years with −11.5 × ln(HR), the “speed of ageing” conversion described by David Spiegelhalter in the BMJ (2012). The result shows the starting point from the table, a line for each answer that moved it, and a link to each study. Because the line between ten-year points is straight, the starting figure can differ slightly from the single-year value in SSA’s full table.
Your answers stay in your browser. They’re saved only in the page address after the # sign, so a shared link carries them with it.
Habits in the estimate, and their limits
The eight habits are smoking, alcohol, daily steps, exercise, sleep, coffee, nuts and spicy food. To see each one’s effect side by side, with the journal and study size, use the habits and longevity calculator. In this model, smoking now takes away 10 years, while 10,000 or more steps a day adds 3 years.
Treat those figures with care. The studies are observational: they followed large groups and compared people with different habits, so each number is an association, not proof that the habit causes the change. Habits also overlap (people who walk more often exercise more), so adding them up can count the same benefit twice. The total is an illustration of scale.
Why it’s an average, not a prediction
A life table describes a population. Real lifespans spread widely on both sides of the average, and the table knows nothing about you beyond your age and sex. Things that matter a great deal, such as current health conditions, family history, income and where you live, aren’t part of the estimate.
That makes the calculator useful for perspective and rough planning, for example seeing how many weeks a typical person your age has ahead on the life in weeks chart, or thinking about how long savings may need to last. It isn’t medical advice and can’t stand in for a conversation with a doctor about your own health. If a number worries you, talk to a doctor or another qualified professional rather than reading too much into an average.
Frequently asked questions
What is the average life expectancy in the US?
In SSA’s 2023 period life table, used in the 2026 Trustees Report, it’s 75.79 years at birth for males and 81.06 for females. Other agencies publish their own figures, which can differ slightly in method and population.
Does life expectancy go up as you get older?
The years remaining go down, but the age you can expect to reach goes up. In the 2023 table, a newborn girl averages 81.1 years, while a 65-year-old woman averages about 85.7.
How accurate is a life expectancy calculator?
It gives an average for people of your age and sex who answer the same way, not a forecast for you. Health, genes and circumstances it doesn’t ask about can move a real lifespan far from the average.
What is a period life table?
A table that applies one calendar year’s death rates at every age to a hypothetical group, giving survival odds and average remaining years at each age. It’s a snapshot of current conditions.
Can changing my habits change my life expectancy?
Large studies link habits such as not smoking and staying active with longer average lives, but they show associations, not guarantees. For advice about your own health, talk to your doctor.