Age Calculator
How it works
The age calculator works out exactly how old someone is on a given date. Enter a date of birth, and optionally change the "Calculate as of" date, which starts on today. The result is broken down into whole years, months and days, the same way you would count on a calendar.
The calculator subtracts the birth year, month and day from the chosen date. If the day of the month hasn't been reached yet, it borrows one month and adds the number of days in the previous month. If the month hasn't been reached yet, it borrows one year and adds 12 months. For example, someone born on March 20 is 0 months and 30 days past their birthday on April 19, because a full month isn't complete until April 20.
Below the main result you will see how many days remain until the next birthday, plus your age as total days, weeks, hours and months lived. Total days are counted between the two dates, total weeks are total days divided by 7 and rounded down, total hours are total days x 24, and total months are years x 12 plus the extra months.
Frequently asked questions
How do I calculate my exact age?+
Enter your date of birth and the calculator subtracts it from today's date, giving your age in years, months and days. You can also pick a different date to see how old you were or will be on that day.
How many days until my birthday?+
The calculator shows the number of days from the chosen date to your next birthday. If your birthday falls on the chosen date itself, it counts ahead to the following year.
How many days old am I?+
Look at "Total days lived" under the main result. It counts every day between your date of birth and the chosen date, and the rows below convert that into weeks and hours.
Can I calculate age on a past or future date?+
Yes. Change the "Calculate as of" date to any date after the date of birth, for example to check an age requirement on a specific day.