Date tool
Age Calculator
Calculate completed age in calendar years, months and days from a date of birth.
How the age calculator works
The result counts completed calendar units rather than estimating age from an average year length.
How to use it
- Select your date of birth.
- Select Calculate age.
- Read the completed years, months and days.
Method
Age = completed years + completed months since the last anniversary + remaining calendar days
Example
Someone born on 10 January 2000 is 25 completed years old on 10 January 2025.
Notes and limitations
The calculation uses the date on your device. February 29 birthdays use February 28 in non-leap years. Legal age rules can vary by jurisdiction, so verify official requirements separately.
Frequently asked questions
How is age calculated?
It counts completed years, completed months and remaining days.
How are February 29 birthdays handled?
February 28 is treated as the anniversary in non-leap years.
Can I enter a future birth date?
No. The calculator displays a validation message.