How it works
The page compares calendar dates and accounts for month/day boundaries.
Reference date defaults to today.
Calculate age precisely.
Calculate age from a birth date to today or a custom reference date, including next birthday.
AgeReady
Choose a birth date.
Practical examples
- Calculate exact age for a birthday, form, or event date.
- Use a custom reference date for historical or future comparisons.
- See days until the next birthday.
How to read the result
- The result separates years, months, and days.
- Total days and approximate weeks provide elapsed-time context.
- Next birthday uses the selected reference date.
Limits and privacy notes
- Time zones can affect date parsing near midnight.
- Historical calendar differences are not modeled.
- Dates stay local in the browser.
Today or another date
- Use today's date for current age.
- Use a custom reference date for forms, events, or historical checks.
- The next-birthday line is calculated from the reference date.
Beyond calendar age
- Total days help with exact elapsed-time questions.
- Approximate weeks are useful for planning.
- Years/months/days are calendar-based.
Midnight boundaries
- Browser date parsing can differ near midnight.
- Calendar reforms and pre-modern local calendars are outside scope.
- Review official forms carefully.