Date & Time
How to Calculate Age
Exact age is usually expressed in completed years, then remaining months and days. This matters for forms, school, legal dates and personal milestones.
Open the age calculatorCount completed years first
Start by counting how many birthdays have fully passed between the birth date and the target date.
If the birthday has not happened yet in the target year, subtract one year from the simple year difference.
Then calculate remaining months and days
After completed years, compare the month and day parts to find the remaining months and days.
Leap years and month lengths can make manual calculations tricky, which is why an age calculator is useful.
Frequently asked questions
Why is exact age not just current year minus birth year?
Because the birthday may not have happened yet in the current year. Exact age depends on the month and day too.
Related calculator
Age Calculator
Calculate your exact age in years, months and days from your date of birth. Also see total days lived and how many days remain until your next birthday.
Use the calculator