How it works
Completed years = difference in calendar years, minus one if the birthday has not yet occurred.
A worked example
Someone born 15 June 1990 is 36 completed years old on 23 September 2026.
What to keep in mind
Uses calendar dates in UTC to avoid daylight-saving offsets. A 29 February birthday reaches the next age on 1 March in non-leap years. Legal rules can differ.
How age is calculated
Your age is the number of full years since your date of birth. If your birthday has not happened yet this year, the calculator subtracts one. It also shows the total number of days you have lived.
Age on a specific date
Change the second date to check how old someone was or will be on a particular day, for example for a school year, a pension date or an age limit.
Leap-year birthdays
If you were born on 29 February, the calculator treats 1 March as your birthday in years that are not leap years.
Frequently asked questions
How many days old am I?
Enter your date of birth and today’s date. The result shows the total number of days lived.
Can I calculate age on a future date?
Yes. Choose any reference date on or after the date of birth.
Can I calculate age on a future date?
Yes. Choose any reference date on or after the date of birth.
Results use the assumptions above. Check critical measurements and dates independently.