Your starting number comes from the Social Security Administration's 2023 period life table, the same table the government uses to plan Social Security. It shows, for every age from 0 to 119, how many more years the average American man or woman of that age can expect to live, and how many people reach each birthday.
The habit questions then nudge that number up or down. These adjustments are rough, rounded figures drawn from large studies (see sources below), and they shrink as you get older, since there are fewer years left for a habit to affect. The "chance of reaching 90 or 100" figures use the life table alone.
One thing that surprises people: your life expectancy goes up as you age. A baby girl born today is expected to reach about 81, but a woman who is already 65 can expect to reach about 86, because she's already made it past the risks of earlier life.
What helps you live longer
Not smoking is the single biggest factor most people control: the CDC estimates smokers lose at least 10 years. After that come staying active (150 minutes a week of brisk walking is linked with about 3.4 extra years), keeping a healthy weight, drinking little or no alcohol, sleeping well and staying socially connected. Regular checkups help catch problems like high blood pressure early, when they're easiest to treat.
Living longer also means planning for a longer retirement. If the result above is older than you expected, it's worth checking that your savings will last with our retirement calculator.
Common questions
What is the average life expectancy in the U.S.?
According to the Social Security Administration's 2023 period life table, life expectancy at birth is about 75.8 years for males and 81.1 years for females.
Why does my life expectancy go up as I get older?
Life expectancy at birth includes everyone, including people who die young. Once you've reached a given age, you've already survived those earlier risks, so your expected total age rises. For example, a 65-year-old woman can expect to live to about 86, older than the 81 expected at birth.
How much does smoking shorten life expectancy?
The CDC says life expectancy for smokers is at least 10 years shorter than for nonsmokers. Quitting before about age 40 reduces the risk of dying from smoking-related disease by about 90%.
Does exercise really add years to your life?
Yes. A large study of over 650,000 adults (Moore et al., 2012) found that 150 minutes a week of brisk walking or similar activity was linked with about 3.4 more years of life compared with no leisure-time activity.
How accurate is a life expectancy calculator?
It gives an average for people like you, not a prediction for you personally. Your family history, health conditions, income, where you live and future medical advances all matter, so treat the result as a starting point for planning.