Age Calculator
Calculate exact age in years, months, and days from a birth date, instantly in your browser.
How to use the Age Calculator
- Enter the date of birth.
- Optionally set an "as of" date to calculate age on a past or future date. It defaults to today.
- Click Run to see the exact age, total days lived and days until the next birthday.
How the Age Calculator works
The calculator counts calendar-accurately rather than dividing days by 365. It first counts complete years, then complete months, then the remaining days, borrowing from the previous month when needed. That handles months of different lengths and leap years correctly.
Total days lived is the exact number of days between the two dates. For someone born on 29 February, the next birthday in a non-leap year is counted as 1 March.
Frequently asked questions
- Is this tool free?
- Yes. Calculate age at no cost, with no account required.
- How is age calculated?
- Age is calculated calendar-accurately in years, months, and days, accounting for varying month lengths and leap years.
- Can I calculate age as of a different date?
- Yes. Set the optional 'As of date' field to calculate age at any point in time, not just today.