Personal

Age Calculator

Enter a birth date to see exact age in years, months, days, weeks, hours and seconds — plus zodiac sign, birthstone, day of the week you were born, and a live countdown to your next birthday.

Birth date

Defaults to today. Set any date to compare.

Your exact age

Age
Total days lived
Total weeks
Total months
Total hours (approx.)
Day you were born
Western zodiac
Chinese zodiac
Birthstone
Birth flower
Next birthday
Days until next birthday

How the age calculator works

Calculating exact age sounds trivial — until you account for varying month lengths and leap years. The standard method is:

  1. Subtract the years between birth date and target date.
  2. Subtract the months. If the target month is earlier than the birth month, borrow a year (subtract 1 from the year count, add 12 to the month count).
  3. Subtract the days. If the target day is earlier than the birth day, borrow a month from the previous month's actual length.

The calculator runs that arithmetic in UTC to avoid timezone drift, so results are identical on every device.

Beyond a number

Age can be more than years. The calculator also surfaces:

  • Day of birth — the weekday you were born on.
  • Western zodiac — based on the Sun's calendar position at birth.
  • Chinese zodiac — derived from the Chinese 12-year cycle.
  • Birthstone & flower — traditional symbols for the birth month.
  • Next birthday — exact countdown updated live.

You can also compare ages between people: just plug each person's birthday into the "Calculate as of" field for a rapid age difference.