Birthday Calculator
Find your next birthday, how many days away, and the weekday.
100% runs in your browser — no upload, no trackingDates are calculated with the standard Gregorian calendar. Results are estimates for general use, not legal or official records.
How it works
Age is measured the calendar way: we count full years, then remaining months, then days — not a simple divide by 365. Date differences use the exact number of midnights between two dates, so a leap year or a short month is handled correctly. Business-day counts loop through the range and drop Saturdays and Sundays. Enter your birth date; the calculator shows your next birthday and how many days away it is.
FAQ
How is age calculated?
Age uses the calendar method: full years, then remaining months, then days. It is not a simple divide by 365, so leap years and short months are handled correctly.
Does it skip weekends?
On the business-days tool, weekends are excluded. On other tools the count is every calendar day unless you tick the skip-weekends option.
Is my date uploaded?
No. All math runs in your browser; the dates you enter never leave your device.
How accurate is it?
It follows the standard Gregorian calendar. It is for general use, not for legal, payroll, or official records.