Age Calculator
Accurate calendar math factoring leap years and exact time elapsed
Calculate a calendar age from a birth date to a chosen date. Review years, months and days, along with elapsed totals and the next birthday.
- Choose today or a custom comparison date
- Break age into calendar years, months and days
- Review the next birthday and elapsed totals
Set both dates deliberately
Enter the birth date and the date on which to measure age. A date before the birth date is not a valid age interval.
Use calendar-aware intervals
Months are not treated as a fixed 30-day unit. Month-end calculations clamp an anniversary to the last available day when necessary.
Understand leap-day birthdays
In a non-leap year, this calculator uses February 28 for a February 29 anniversary. A legal or administrative rule may use a different convention.
Separate age from eligibility rules
The result is a date calculation, not confirmation of eligibility for a service, benefit or legal requirement. Check the applicable rule independently.