Calculators ·
How to Calculate Your Exact Age
Learn how age is calculated in years, months and days and why the result is different from simply subtracting birth years.
Why exact age is more than a year difference
Subtracting birth years gives a rough result. Exact age also depends on whether the birthday has already occurred in the current year and on the number of days in the relevant months.
Years, months and days
An age calculator compares the birth date with the target date and works through calendar years and months before calculating the remaining days. This produces a calendar-based age rather than an approximation.
Leap years
Leap years add an extra day to February. Calendar-based calculations therefore need to account for the actual dates involved rather than assuming every year has the same number of days.