🎂 Age Calculator

Enter your birth date to find your exact age in years, months, and days.

Date of birth

As of date

Your age is calculated exactly, accounting for leap years and varying month lengths.

How age is calculated

Your age isn't just "today's year minus your birth year" — that shortcut breaks the moment your birthday hasn't happened yet this year. This calculator does it properly by comparing full calendar dates: it counts complete years, then the remaining complete months, then the remaining days, adjusting automatically for how many days are in each month and whether a leap year (like 2024 or 2028) falls in between.

The method, step by step

Subtract the birth year from the "as of" year to get a starting year count.
Compare months: if the current month/day hasn't reached the birth month/day yet, subtract one year and add 12 to the month count.
Compare days the same way, borrowing days from the previous month if needed.
The result is your precise age in years, months, and days — plus the total number of days you've been alive.

Worked example: Born March 15, 2000, checked as of September 24, 2026 → that's 26 years, 6 months, 9 days old (9,689 total days). The extra 9 days come from counting past August 24 to September 24, minus the 15 days needed to reach the 15th.

Common uses for an age calculator

Eligibility checksConfirm you meet a minimum age for a job, license, retirement benefit, or contest entry.

Legal & medical formsMany forms ask for exact age in years and months rather than just a birth date.

Pet & milestone trackingConvert a pet's or child's birth date into a precise age for records or vet visits.

CuriosityFind out exactly how many days old you are, or how old you'll be on a future date.

Frequently asked questions

Does this account for leap years?

Yes. Because the calculator compares full calendar dates rather than estimating with a fixed 365-day year, leap days (February 29) are automatically included in the day and total-day counts.

Can I calculate age as of a past or future date?

Yes — change the "As of date" field to any date, past or future, to see how old someone was, or will be, at that point in time.

Why do total days differ from years × 365?

Because leap years add an extra day roughly every four years, and the number of days in each month varies. The total-day count reflects the exact number of calendar days between the two dates.

Is my birth date stored anywhere?

No. All calculations run locally in your browser using JavaScript — no dates are sent to a server or saved.