Age Calculator
Calculate exact age in years, months, days, and total days from a birth date and an as-of date.
The calculator compares calendar dates only, so timezone and time-of-day changes do not affect the result.
Result
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Result
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Age CalculatorEnter the birth date, then choose the date you want to calculate age against.Read the exact years-months-days age separately from total days; they answer different questions.For enrollment dates, birthdays, or deadlines, change only the as-of date.
Quick Start
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Common Scenarios
Birthdays and anniversaries
check how many full years, months, and days have passed.
Age on a selected date
see age on a past or future calendar date.
Total days
useful for records, planning, or rough day-count checks.
Usage Advice
Dates are treated as calendar days, not timezone timestamps.
Total days uses the gap between dates; add one yourself if your workflow counts the start day.
If your browser does not show a date picker, enter dates as YYYY-MM-DD.
Limitations & Compatibility
This tool does not interpret birth time, birthplace, timezones, or astrology-style rules.
Schools, exams, insurance, or legal age cutoffs can have their own inclusion rules.
Leap-day birthdays are calculated by calendar math; verify separately if an organization treats Feb 29 as Feb 28 or Mar 1.
Privacy & Security
Your dates are calculated in your browser and are not uploaded to a server.
FAQ
It counts full years first, then full months, then the remaining days.
The calculator reports the day gap between two dates and does not count the start date as day one.
Yes. Set the as-of date to a future date, as long as the birth date is not after it.