How to use it
- Enter the date of birth.
- Keep today as the reference date or choose another one.
- Read the age, the total days and the countdown to the next birthday.
How it works
Age is counted the way you would on a wall calendar: whole years first, then whole months, then the days left over. Months have different lengths, so “1 month” from January 31 lands on the last day of February rather than spilling into March. Total days are a straight count between the two dates, in UTC so time zones and daylight saving can't shift it by one.
Worked example
Born July 14, 1990, on October 20, 2026: 36 full years takes you to July 14, 2026, three more months to October 14, then 6 days. Age: 36 years, 3 months and 6 days, which is 13,247 days in total. The next birthday is 267 days away.
Assumptions and limits
- Leap-day birthdays move to March 1 in common years, a widely used legal convention. Some systems use February 28 instead, so a legal deadline may differ by a day.
- This is the Gregorian calendar. Ages in the Hijri calendar or East Asian age reckoning come out differently.
- Time of birth is ignored.
Frequently asked questions
How are months and days counted?
Full calendar months are counted first, then the remaining days, the same way you would count on a calendar.
What about people born on 29 February?
In non-leap years the next birthday is shown as 1 March, which is the convention used by many countries.
Is my birth date stored?
No. The calculation runs entirely in your browser.