Age Calculator
Calculate exact age in years, months and days from a birth date.
How the age calculator works
The calculator compares your date of birth with a selected date and returns a calendar-based age.
Why exact age can be tricky
Months have different lengths, and leap years add an extra day.
Calendar age vs total days
An exact calendar age is normally expressed in years, months and days rather than by dividing total days by 365. Month lengths and leap years vary, so calendar arithmetic gives a more intuitive result around birthdays and month boundaries.
Age calculations across time zones
For ordinary birthday calculations, the selected calendar dates are usually sufficient. Legal age rules, eligibility deadlines or events tied to an exact timestamp can depend on local law and time zone, so verify those cases against the relevant official rule.
Frequently Asked Questions
Does the calculator handle leap years?
Yes. It uses real calendar dates.
Does a leap-day birthday change the age calculation?
The elapsed calendar age can still be calculated normally, but how a February 29 birthday is treated in non-leap years for legal purposes can vary by jurisdiction.
Why is age in days different from years times 365?
Leap years and different month lengths mean calendar years do not all contain exactly 365 days.