How the age is worked out
The calculator counts the same way you would on a calendar. First it counts whole years from your date of birth, then the whole months left over, then the remaining days. Leap years are handled automatically, because it uses real calendar dates rather than an average year length.
A month is counted from one date to the same date in the next month, like 14 March to 14 April. If that date doesn't exist, like the 31st in a 30-day month, the last day of the month is used instead.
Everything runs in your browser. The dates you enter aren't sent anywhere.
Questions people ask
What if I was born on 29 February?
In years without a 29 February, this calculator treats 28 February as your birthday for the countdown. Some people celebrate on 1 March instead. Your age in years, months and days is the same either way.
Why might my age in days differ from another site?
Some sites estimate using 365.25 days per year. This one counts the actual days on the calendar between the two dates, so it's exact.
Can I find someone's age on a past or future date?
Yes. Change the “Age on this date” field to any date and the answer updates instantly.
Does it count the day I was born?
Age is counted the usual way: on your birthday you've completed a whole year, so the day of birth itself isn't added as an extra day.