About the age calculator
Enter a date of birth to get an exact age in years, months, and days. You can also choose another date to find someone’s age on that day — useful for forms and eligibility checks.
How to use this calculator
- Enter the date of birth.
- Optionally choose a different “as of” date.
- Read the age and totals.
Worked examples
- 36 years
- 9 months, 25 days
36 years, 9 months, and 25 days.
Measurement guidance
Leap years
Date differences account for leap years automatically.
Frequently asked questions
How are February 29 birthdays handled?
In non-leap years, the next-birthday count uses March 1.
Is my data stored?
No. Calculations run in your browser.