Age Calculator
Work out an exact age in years, months and days, plus the total number of days lived.
Age Calculator
Exact age in years, months and days, plus total days lived.
Leave blank for today
Enter a date of birth.
A Feb 29 birthday turns over on Feb 28 in non-leap years. Leave “As of” blank to use today.
How it works
Enter a date of birth. The “As of” date is optional — leave it blank to use today. The result is the number of complete years and months since the birth date, plus the leftover days.
- A Feb 29 birthday turns over on Feb 28 in non-leap years.
- Total days counts whole days from the birth date up to, but not including, the as-of date.
Method
months = largest whole number of months such that birth date + months ≤ as-of date
years = months ÷ 12 (whole), months = remainder, days = as-of date − (birth date + months)
Worked example: Born 1990-06-15, as of 2024-03-10: 33 years, 8 months, 24 days (12,322 days in total).
More examples and edge cases
- Leap-day birthday: born 2000-02-29, the age on 2023-02-28 is already 23 years, 0 months, 0 days, and on 2023-03-01 it is 23 years, 0 months, 1 day
- Born on the as-of date itself: 0 years, 0 months, 0 days (0 days in total)