Age Calculator
Find age as years, months, and days from a date of birth to today or to another date you choose.
Leave blank to use today.
About this calculator
Age is the elapsed time from a date of birth to a chosen date, usually today. This calculator uses calendar months and days rather than dividing total days by 365, which keeps month lengths accurate.
How to calculate
Enter the date of birth. Optionally set an “age at” date if you need age on a past or future day. The result includes years, months, days, and total days.
Age = calendar difference from birth date to the selected date, adjusting months and days when the day-of-month has not been reached yet.
When to use it
- Age on a form or application
- Age on a future date
Examples
Born 15 March 2000, measured on 15 March 2026
The age is exactly 26 years, 0 months, and 0 days.
Same birthday, different years
| Birth date | On | Age |
|---|---|---|
| 15 Mar 2000 | 15 Mar 2026 | 26 years exactly |
| 29 Feb 2004 | 1 Mar 2025 | 21 years, 0 months, 1 day |
FAQ
Does this account for leap years?
Yes. The calculator uses real calendar dates, so 29 February births and leap days are handled by the date itself.
Can I calculate age on a future date?
Yes. Set the “Age at date” field to any valid date after the date of birth.