Age Calculator
Find the exact age in years, months, and days between two dates.
Try an example
26y 8m 8d
Born on a Saturday
9,748
1,392 weeks
114 days
Falls on a Friday
About this calculator
How This Age Calculator Works
Enter a birth date (and optionally a different "as of" date), and the calculator returns the exact age in years, months, and days — plus total days and weeks lived, which day of the week you were born on, and a countdown to the next birthday.
How the Count Works
The calculator counts full years first, then full months within the current year, then whatever days are left over — the same way you'd count age by hand. It correctly accounts for different month lengths and leap years, so it doesn't just divide total days by 365.25 the way a rough estimate would.
Common Uses
Beyond curiosity, exact age calculations come up for eligibility checks (age requirements for programs, benefits, or events), legal and medical contexts where precise age matters, and simply finding out how many days old you or someone else is.
Worked example
From a birth date of January 1, 2000 to a target date of June 15, 2025, the exact age is 25 years, 5 months, and 14 days.
Frequently asked questions
How is the age broken into years, months, and days?
It counts the number of full years first, then full months remaining, then whatever days are left over — the same way you'd count age by hand on a calendar.
Can I calculate age as of a date other than today?
Yes — the "as of" date defaults to today but can be set to any past or future date, useful for figuring out age at a specific event.
How does this handle leap years?
Calculations are based on actual calendar dates, so leap years (and February's 28 or 29 days) are accounted for automatically rather than assuming a fixed 365-day year.
What if the target date is before the birth date?
The calculator expects the "as of" date to be on or after the birth date — reverse them if you get an unexpected result.