Age calculator
What is an Age Calculator?
Working out an exact age by hand is surprisingly fiddly: months have different lengths, leap years add a day, and birthdays on 29 February only exist every four years. This age calculator handles all of that and gives you your age as years, months and days, along with totals in weeks, days and hours and the number of days until your next birthday.
How to use it
- Pick or type the date of birth.
- Optionally change the reference date to calculate the age on a past or future day, for example on an exam date or a retirement date.
- Read the age breakdown and the next-birthday countdown.
Worked example
Someone born on 14 March 1990 is, on 27 October 2026, 36 years, 7 months and 13 days old. The calculation first counts whole years (1990 to 2026 is 36 once 14 March has passed), then whole months from 14 March to 14 October (7), then the remaining days from 14 October to 27 October (13).
Things to know
- Leap-day birthdays. For people born on 29 February, the birthday in non-leap years is usually counted on 28 February or 1 March depending on local law. The calculator shows the countdown so you can see which day applies.
- Legal age vs. elapsed time. In most countries you reach a new age at the start of your birthday. Some legal systems count it from the day before, so check local rules for official documents.
- Time zones. Age is calculated from calendar dates, not from the hour of birth.
Your date of birth is processed only in your browser and is never stored or sent anywhere.
Frequently Asked Questions
How is age calculated in years, months and days?
The calculator counts complete years first, then complete months after the last birthday, and finally the remaining days. This matches how age is normally stated on forms.
Can I calculate age on a specific date?
Yes. Change the reference date to any day in the past or future to see how old someone was or will be on that date.
How are leap years handled?
Leap years are taken into account automatically, so totals in days and weeks are exact, including 29 February.
Is my date of birth saved?
No. The calculation runs entirely in your browser and nothing is uploaded or stored on a server.