Age calculator
Work out an exact age in years, months and days from a date of birth, plus totals and the countdown to the next birthday.
Enter a date of birth to see the exact age, totals and the next birthday.
How the age is worked out
The calculator counts full years between the two dates, then the whole months left over, then the remaining days. Because it steps down through real calendar months, the figure matches the age you would give in conversation rather than a rough days-divided-by-365 estimate.
Worked example. Someone born on 15 March 1990, measured on 10 July 2026, is 36 years, 3 months and 25 days old. That is about 1,891 weeks, or roughly 318,000 hours.
Totals and the next birthday
Under the headline you get the same age expressed in months, weeks, days and hours. The calculator also shows the weekday the person was born on and counts the days to their next birthday, with the weekday it falls on.
What day of the week were you born?
The calculator tells you, underneath the age. Put in a date of birth and it names the weekday, worked out from the real calendar rather than a rule of thumb, so it is right for any date including ones before you were born and well after.
It also gives the weekday of your next birthday, which is the more useful half if you are trying to work out whether to take the Friday off.
Leap years and 29 February
Day counts are exact, so leap years are handled without a fudge. A birthday on 29 February is counted against the real calendar, and spans that cross one or more leap years come out right.
Common questions
How is the age worked out?
It counts full calendar years first, then the leftover months, then the leftover days. A month is a real calendar month, not a flat 30 days, so the result matches how you would say your age out loud.
Can I find my age on a past or future date?
Yes. Set the “age at date” field to any date. Leave it blank and it uses today.
Does it handle leap years?
Yes. The day count is exact, so people born on 29 February and spans that cross leap years are counted correctly.
What day of the week was I born on?
Enter your date of birth and the calculator names the weekday under the age, along with the weekday of your next birthday. It reads the real calendar, so it is right for any date.