How age is calculated
Age is counted the way people normally count it: full years since your last birthday, then full months since the last "month-day", then remaining days. When the day of the month hasn't been reached yet, the calculator borrows the number of days in the previous month, so results stay correct across 28-, 30- and 31-day months and leap years.
Example: someone born on June 15, 1990 is 36 years, 4 months and 28 days old on November 12, 2026, which is 13,299 days.
Dates are compared as calendar dates, not clock times, so the result doesn't shift with your time zone.
Leap-day birthdays
If you were born on February 29, this calculator treats February 28 as your birthday in non-leap years. Some places legally use March 1 instead.
Frequently asked questions
How do I calculate age on a specific date?
Change the "Age on this date" field. It defaults to today, but you can enter any past or future date, for example to check eligibility for a cutoff date.
How many days old am I?
Enter your birth date and the "Total days" row shows the exact number of days since you were born, counting today.
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