Age Calculator
Calculate age in years, months and days on a chosen date.
How to use this tool
Choose a date of birth and the date on which you want to calculate the age. The second date defaults to today on your device. Future birth dates relative to that date are rejected.
A worked example
For a birth date of 15 January 2000 and an end date of 23 September 2026, the result is 26 years, 8 months and 8 days.
How it works & what to check
The calculator counts full calendar years and months, then remaining days. If the birth day does not exist in the target month, it uses that month’s final day. Total days are calculated from calendar dates without daylight-saving offsets.
Common questions
How are leap-day birthdays handled?
For a 29 February birthday, the anniversary is treated as 28 February in a non-leap year. A legal or administrative age rule may use a different convention.
Can I calculate age on a past date?
Yes. Change the end date to the date you need, provided it is not before the birth date.
Is my date of birth saved?
No. This calculator uses the dates in the current page and does not send them to a server.