How the age is counted
The calculator counts the way people count on a calendar. It first finds the number of full years since the birth date, then the full months after that, and finally the days left over. Someone born on March 15, 2000 is, on October 14, 2026, 26 years, 6 months and 29 days old.
Months are counted as whole calendar months, not as 30-day blocks. If the birth day does not exist in a month, such as the 31st in a 30-day month, the calculator treats the last day of that month as the anniversary.
Total days and weeks lived
Alongside the years-months-days breakdown you will see the plain total of days since birth, and the same number expressed in weeks. These are handy for milestone posts, like the 10,000th day of a baby's life or a grandparent's 30,000th day.
Leap days are included automatically, so you do not need to adjust anything by hand.
Born on February 29
People born on a leap day have a real birthday only once every four years. In years that are not leap years, the calculator counts the birthday as March 1. Some places and families celebrate on February 28 instead, and that is a perfectly fine choice, but the tool has to pick one rule and uses March 1.
Age on another date
You do not have to measure against today. Choose any other date to see how old someone was or will be on it: at a wedding, on the first day of school, at the date a form asks about, or on the day a historical figure did something notable. The days to the next birthday are always counted from the date you choose.
Questions people ask
Why do my months look off by a day compared with another calculator?
Tools disagree when a birth day such as the 31st is missing from a month. This one moves the anniversary to the last day of the shorter month.
Does it count the day I was born?
Total days are the number of days between the two dates, so the birth date itself is day zero and your first birthday is day 365 or 366.
Can I calculate someone else's age?
Yes. Enter any birth date. Nothing is stored or sent anywhere, so it is fine to look up family and friends.