Age Calculator
Enter a date of birth to get an exact age, a countdown to the next birthday and the weekday you were born. Change the “as of” date to find someone’s age on any day.
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How your age is counted
Age is counted the way people say it: whole years since your last birthday, then whole months since the last monthly anniversary, then the remaining days. Totals in weeks, days, hours and minutes count from midnight on your birth date to midnight on the “as of” date, so hours and minutes are whole-day figures — your birth time isn’t used.
Leap-day birthdays. If you were born on February 29, your birthday only exists one year in four. Some places treat February 28 as the legal birthday in common years and others use March 1, so you can pick either. The choice changes your next-birthday date and, for a day each year, your age in years.
Chinese zodiac signs change at Chinese New Year (late January to mid February), not January 1. Where your browser supports the Chinese calendar, the sign is worked out from the lunar year you were born in, so an early-February birthday gets the right animal.
Questions
How do I calculate my exact age?
Count full years since your last birthday, then full months since the last monthly anniversary, then the days left. Enter your date of birth above and the calculator does this for you, including leap years.
How old will I be on a certain date?
Change the “Age as of” date. The age, the totals and the milestone table all recalculate for that day, which is useful for school entry, retirement or visa cut-off dates.
What day of the week was I born?
It’s shown under “Born on”, along with the day of the year, your star sign and your Chinese zodiac animal and element.
When is my 10,000th day?
10,000 days after your birth date, a little over 27 years and 4 months. The milestones table lists it with other round numbers such as 1,000 weeks, 500 months and 1 billion seconds (about 31 years 8 months).
Is my date of birth stored?
Only in this browser’s local storage so the page remembers it next time. It is never sent anywhere.