Age Calculator
This calendar-aware calculator uses local date-only values, including real month lengths and leap years.
Loading calculator…
Browser-only processingCalculations are performed locally in your browser. Your entered values are not sent to our servers.
Age Calculator formula
Calendar age is found by borrowing actual months and days rather than dividing elapsed days by 365.
Worked example
Someone born March 10, 2000 is 25 years old on March 10, 2025.
How to use this calculator
- Enter the date of birth.
- Choose the date on which to calculate age.
- Select Calculate age.
Important assumptions and limitations
A birth date after the as-of date is invalid. Leap-day birthdays are handled using calendar dates.
Related calculators
Percentage CalculatorCalculate percentages, percent change, increases and decreases.Discount CalculatorFind sale price, sequential discounts, tax and total savings.Date Difference CalculatorFind calendar and total time between two local dates.Profit Margin CalculatorCompare profit margin and markup or calculate a target selling price.
Frequently asked questions
Does this use my local date?
Yes. The default as-of date is created from your browser’s local calendar date.
Is a year treated as 365 days?
No. Exact age uses calendar years, months and days.