Life in Months Calculator
One dot for every month. Set your age and sex to see the months you have lived and the months ahead, on average.
Select your age
40
A 40-year-old, on average
LivedAheadOn the table
Green is the months your habits could add. Want to see how many green months you have on the table?
Set your age and sex and they carry over to the assessment, which asks the rest. Free. Nothing you set here leaves your browser.
How many months do you have left?
On average, a 40-year-old woman has 538 months ahead and a 40-year-old man has 490. At 60 it is 312 months for a woman and 277 for a man. Each dot in the picture is one of those months. Grey is a month you have lived, your age times twelve. Purple is a month ahead on the average for people who have already reached your age, so a 60-year-old sees more purple than subtracting 60 from life expectancy at birth would give. Why your life expectancy goes up as you get older explains that.
Green is a month your habits could add. The page knows only your age and sex, so it draws no green. The assessment asks your age and then a dozen questions, and your results draw the green months at the end of the purple ones. Your life in months is one of the three cards you can share from your results.
Where the average comes from
The purple count is the average for people who have already reached your age, from the CDC's 2024 United States life tables (NVSR 75-05), read for your age in years and your sex, with a small allowance for mortality continuing to improve. A 40-year-old woman has 44.8 more years on average, which is 538 months. A 40-year-old man has 40.8, or 490 months. If you would rather not say, the page uses the midpoint of the two.
It is an average, not a prediction about a person. It knows nothing about your habits, your health or your family, and it describes the United States. In a country whose life expectancy differs from the U.S. figure, the purple will be off by roughly that difference, and by less at older ages. The life expectancy calculator starts from the same average and adds smoking, activity, height and weight.
Why months
A year is easy to wave away. A month is one dot, small enough to count and big enough to notice. Forty years is a number. Four hundred and eighty dots is a picture. The grid makes the time ahead concrete without making it a countdown, and it never shows a date.
How it is made
The page runs in your browser. It uses the same arithmetic and the same three colors as the life-in-months card in your results and your report, the years times twelve, rounded to the nearest month. Here the purple is the average. In your results it is your own estimate. Nothing you set here leaves the page, and nothing is stored until you tap the button, when your age and sex carry over to the assessment. The methodology page has every source behind the estimate and what it cannot tell you.
Frequently asked questions
How many months do I have left?
On average, a 40-year-old woman has 538 months ahead and a 40-year-old man has 490. Set your own age and sex above to see yours as dots. It is the average for people who have already reached your age, not a prediction about you. Your own number moves with your habits.
Why months and not weeks?
A life in weeks is about four thousand dots, too many to read on a phone. A month is one dot you can see. To count in weeks instead, multiply the years by 52.
What are the green months?
The months your habits could add. The assessment asks your age and then a dozen questions about how you live. It moves every habit you answer to its best answer, counts the years that would add, and your results draw those months in green at the end of the purple. It takes about 2 minutes and it is free.
Is anything I set here saved?
Not unless you tap the button. Nothing you set here leaves your browser. When you tap it, the age and sex you chose stay on your device so the assessment can start from them. It is free, and no account is needed.