Age Calculator
Calculate completed calendar years, remaining months and days between two dates.
Make this result useful
Use it now, or keep a copy for later. We never save your tool input automatically.
How to use this tool
Select a birth date and the date on which to calculate age, then select Calculate.
Important to know
Calculate completed calendar years, remaining months and days between two dates.
Dates are compared as UTC calendar dates, without times or time zones. The birth date cannot be after the as-of date. Leap-day anniversaries follow calendar-date differences.
Formula and methodology
Use the calendar interval from birth date to as-of date for completed years, months and days; elapsed days is the date difference.
Example
From 1 January 2000 to 1 January 2025 is exactly 25 completed years.
Frequently asked questions
Does the calculator include the time I was born?
No. It compares dates only, so times of day do not affect the result.