Dates & Time

Age Calculator (Years, Months, Days from Birthdate)

Enter a date of birth and it returns your exact age in years, months, and days, plus total days lived, the weekday you were born, and days to your next birthday. Set any reference date to project age forward or back.

How to use
  1. Enter the date of birth.
  2. Optionally set a reference date other than today.
Reference
Exact age

Total days
Total weeks
Total months
Next birthday
Born on a
Generation
Zodiac
Chinese zodiac
Date math uses your inputs as given; check time-zone and leap-year edge cases.
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How it's calculated

age = reference date − birth date (split into years, months, days)

Counts full years, then the remaining months and days between birth date and the reference date, borrowing days from the previous month and months from the year as needed. Also derives total days, weeks and months lived.

Common questions

How is exact age calculated?

It counts full years, then the remaining months and days to the reference date, accounting for leap years and uneven month lengths.

Can I find my age on a future date?

Yes. Set the reference date ahead of today to see how old you'll be then.