Age calculator
Enter a date of birth. Change the second date to see the age on any other day.
Result
- Total months
- Total weeks
- Total days
- Total hours
How age is calculated
Age counts the full years since birth, then the full months after the last birthday, then the remaining days. A person born on March 10 is one month older on April 10 and one year older on the next March 10, the way people usually count.
When the birth day number does not exist in a month (for example, the 31st), that month's step lands on the month's last day, the same rule the add and subtract tool uses.
Birthdays on February 29
In years without a February 29, this calculator treats February 28 as the birthday, so someone born on February 29, 2000 turns 26 on February 28, 2026. Some laws and organizations use March 1 instead. If that matters for your purpose, check the rule that applies to you; the difference is never more than one day.
Total hours assume 24-hour days and are approximate, since the hour of birth is not known.