Age Calculator
Exact age in years, months and days, plus total days and the next birthday.
How to use Age Calculator
- Enter the date of birth.
- Optionally choose another date to calculate age on (for example a deadline).
- Read the exact age and the totals.
How it works
Age is counted in calendar terms: whole years, then whole months, then remaining days, the way people state ages. Months are added with end-of-month clamping, so from 31 January one month later is 28 (or 29) February. Totals in days and weeks count every calendar day.
For people born on 29 February, the birthday in common years is counted on 28 February. Legal rules for when a leap-day birthday falls differ between countries, so check local rules for official purposes.
Example
Born 15 May 1990, on 9 November 2026 a person is 36 years, 5 months and 25 days old.
Frequently asked questions
How is age in months calculated?
Whole years × 12 plus the whole months after the last birthday. The remaining days are shown separately.
Which day of the week was I born?
It is shown in the results, calculated from the date of birth.
Does it handle time zones?
Dates are compared as calendar dates without times, so time zones do not affect the result.
Is my birth date stored?
No. It stays in your browser.
Limitations
- Uses the Gregorian calendar.
- Leap-day birthdays are counted on 28 February in common years.
Last reviewed November 9, 2026. How we build and test tools.