Age Calculator

Enter a date of birth to find the exact age in years, months and days on today’s date or any other date, plus the total in months, weeks and days and the days until the next birthday.

How age is calculated

  1. Subtract the birth year from the current year.
  2. If the birthday has not happened yet this year, take away one year.
  3. Count the full months since the last birthday, then the days since the last monthly anniversary.

If the day of the month is smaller than the birth day, the calculator borrows the number of days in the previous month, the same way you borrow when subtracting by hand.

Worked example

Someone born on June 15, 1990 is 36 years, 4 months and 2 days old on October 17, 2026. That is 13,273 days, or 1,896 weeks and 1 day.

Leap day birthdays

For people born on February 29, the calculator treats February 28 as the birthday in non-leap years for the next-birthday countdown. Legal rules for leap day birthdays vary by country and purpose.

Age in different units

UnitHow it is counted
Years, months, daysCalendar age, as used on forms
Total monthsFull years × 12 + months
Total weeksTotal days ÷ 7, rounded down
Total daysEvery day from birth to the chosen date

Frequently asked questions

How do I calculate my exact age?

Enter your date of birth and today’s date. The calculator finds the full years, months and days between them.

How old am I in days?

The Total days row shows how many days have passed since your date of birth.

Can I find my age on a past or future date?

Yes. Change the "Age on this date" field to any date after your birth date.

Is this the same as chronological age for testing?

Yes, though the chronological age calculator is set up for test scoring and shows the rounded age many test manuals use.

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