Age Calculator
Calculate exact age in years, months and days from a date of birth.
Age
- Total months
- Total weeks
- Total days
Worked example
Someone born on 15 June 2000 is 24 years, 6 months and 16 days old on 31 December 2024.
How we calculated this
Age is calculated using proper calendar arithmetic: completed years, then completed months, then remaining days, not a simple days-divided-by-365 estimate. Someone born on 29 February has their birthday treated as 28 February in a non-leap year, consistent with how this site handles every other end-of-month calendar calculation. The "age on" date defaults to today but can be changed to calculate age on any date. A date of birth after the "age on" date is rejected. Total months is an exact count of completed calendar months (years × 12 + months), not an approximation; total weeks and total days are the exact elapsed calendar-day count, regrouped.
What this result means
The result is your exact completed age in years, months and days as of the reference date, plus the equivalent in total months, weeks and days.
Examples
- Born 29 February 2000, age as of 28 February 2025: 25 years, 0 months, 0 days
- Born 29 February 2000, age as of 1 March 2025: 25 years, 0 months, 1 day
Assumptions and limitations
- Supports dates from the year 1 to the year 9999.