Age
Calculate exact age from birthdate in years, months, and days
How to use Age
- 1Enter the birth date (Y/M/D); add the time for more precision.
- 2Enter the current date (defaults to today).
- 3Read the exact age in years, months, days and total days lived.
How is age calculated precisely?
age = current date − birth date (calendar-aware subtraction)Exact age is not a simple year difference; you must handle borrowing between months and days. If today's day is before the birth day, you borrow from the month and convert to days, giving an accurate years/months/days result.
Total days are useful for milestones, insurance or legal age. Watch time zones and leap years: someone born on 29 Feb is usually counted on 28 Feb or 1 Mar in non-leap years, varying by custom.
Frequently asked questions
Why is subtracting years wrong?
It ignores whether this year's birthday has passed. Step-by-step months/days give the true age.
Born on 29 Feb in a leap year?
In non-leap years it is usually counted on 28 Feb or 1 Mar depending on custom; the tool follows the common rule.
Can it show total days lived?
Yes, the result includes total days from birth to today, with leap-year differences.