How exact age is computed
The calculator counts complete years first, then complete months, then leftover days — correctly handling different month lengths and leap years. It also totals every day you have been alive and counts down to your next birthday.
Chronological age in official use
This year-month-day convention is the one used on official forms, in medicine and in schools, so the result here matches what institutions expect.
Frequently asked questions
How are leap years handled?
The day count uses real calendar dates, so February 29 birthdays and leap years are counted correctly.
Why do different sites give slightly different ages in months?
Month lengths vary, so conventions differ on borrowing days. This tool uses the standard year-month-day method used on official documents.
Can I calculate age at a past or future date?
Yes — change the "as of" date to any date you like.