Age Calculator
Years, months, and days from a birth date.
Loading tool
Enter a birth date and read years, months, and leftover days. Leap days are handled with common civil rules.
How to use this tool
- Set the dates or duration. Pick the clocks, dates, or timer length you need.
- Start or calculate. Run the timer or read the difference. Time zones use this browser.
- Copy the result. Copy timestamps or calendar values into your notes.
Leap birthdays
A 29 February birthday is treated as 28 February in non-leap years for the anniversary, which matches many civil systems but not all statutes.
Frequently asked
Can I see age on a future date?
Yes. Set the as-of date.
Does it use the time of birth?
Optional. Without a time, the count is in whole days.
Is this valid for a passport?
No. Use official documents.
Can I get total days lived?
Yes. A total-days line is included.
Are time zones applied?
The as-of date uses the zone you pick so the birthday line does not slip.