Age Calculator
Enter a date of birth to see exact age in years, months, and days. Optionally choose an “as of” date (defaults to today). All math stays in your browser.
Leave “As of” blank to use today’s date on this device.
Years
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Months
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Days
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Total days
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Result: —
How it works
- Years / months / days use calendar arithmetic (not simply total-days ÷ 365).
- If the day-of-month has not arrived yet in the as-of month, we borrow from the previous month.
- Total days = whole calendar days from birth date to as-of date (UTC midnight).
- Future birth dates show an error instead of a negative age.
Examples
- Born 2000-01-15, as of 2026-01-15 → 26 years, 0 months, 0 days
- Born 2000-01-15, as of 2026-03-20 → 26 years, 2 months, 5 days
- Born 2024-02-29 (leap day), as of 2025-02-28 → age lands on the day before the anniversary in non-leap years (calendar borrow rules apply)
- Born 1990-06-01, as of 1990-06-01 → 0 years, 0 months, 0 days
Age vs date difference
Need raw days/weeks between any two dates? Use theDate Difference Calculator. Step-by-step:how to calculate age from date of birth.
FAQ
Is age calculated in whole years only?
No. We also show remaining months and days after the last birthday anniversary relative to the as-of date.
What if I leave “As of” empty?
The tool uses today’s local calendar date on your device.
Does this handle leap years?
Yes. Day counts and month lengths come from the real Gregorian calendar, including Feb 29.
Is my date of birth uploaded?
No. Calculation runs entirely in your browser.
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