What this calculator does
Use the age calculator to find exact age on a chosen date. It can be useful for eligibility checks, forms, milestones and planning.
Formula used
The calculator compares the date of birth with the chosen date, then counts complete years, complete months and remaining days.
How to read the result
Age can be expressed in different ways depending on the context. Legal, school or medical rules may use their own cut-off dates.
Assumptions
- Uses calendar dates in the browser.
- Does not account for time of day or timezone birth details.
- Requires the end date to be on or after the date of birth.
Sources and checks
This calculator uses a standard public formula. Where rules or thresholds can change, source links are listed on the relevant page.
Frequently asked questions
Why do months vary?
Calendar months have different lengths, so exact age is counted by complete calendar months rather than a fixed number of days.