How age is calculated
Age is the number of full years since birth: this year minus the birth year, minus one if this year's birthday hasn't happened yet. Someone born on October 15, 2000 is 25 until October 14, 2026, and turns 26 on October 15.
The detailed result breaks it down into years, months and days. People born on February 29 are counted as having their birthday on March 1 in non-leap years.
Age on a specific date
Change Age on to any date to find someone's age on that day, which is useful for school entry cutoffs, eligibility rules, insurance or historical dates.
Frequently asked questions
How many days old am I?
The Days lived card shows the exact number of days (and weeks) from your date of birth to the chosen date.
What if I was born on February 29?
In non-leap years the calculator treats March 1 as your birthday for counting age.
Is the Chinese zodiac exact?
It's based on the calendar year. The zodiac year actually starts at Lunar New Year (late January to mid February), so if you were born early in the year, check whether you belong to the previous sign.