Age Calculator

Age calculator at a glance#

An age calculator works out how old you are from your date of birth to a reference date, usually today. It subtracts the birth date from the current date and reports the gap in years, months and days, counting each month at its real length so the result is exact rather than rounded.

To work it out by hand, take the years, months and days of each date and subtract. If the current day is earlier than the birth day, borrow the days from the previous month; if the current month is earlier than the birth month, borrow 12 months from the year count. Leap years are handled automatically, since February gives 29 days in a leap year and the day count for any borrowed month uses that month's true length.

How old am I: worked example#

Say you were born on January 15, 1990, and the reference date is June 15, 2026. The months and days line up exactly (the 15th in both), so the age is 36 years, 5 months and 0 days. Counted a different way, that is 13,300 days old. If you want the answer in total days, weeks or hours instead, the same start and end dates feed every unit.

Enter your date of birth and a reference date in the calculator above for your exact age in years, months and days, plus the total days you have been alive. Hand calculations can drift by a day around leap years or month boundaries, so use the calculator for the precise figure.

How age is calculated#

Your age is the time from your date of birth to a reference date, normally today. The calculator subtracts the two dates and reports years, months and days, counting each month at its real length. Leap years are handled automatically, so February counts 29 days in a leap year and 28 otherwise.

Two dates can also give total days, weeks, hours or minutes from the same inputs. The day count is the cleanest single number: it does not depend on which month boundaries you cross, so it is the unit to use when you compare two ages exactly.

What you can work out#

• Your exact age in years, months and days from a birth date.
• The number of days until a birthday or event.
• The gap between any two dates, in days, weeks, hours or minutes.
• The age difference between two people from their birth dates.
• How long ago a past date was, such as an anniversary.

Ways of counting age#

Most of the world uses chronological age: the number of full years since birth, the figure this calculator returns. A few other systems exist and can differ by a year.

In traditional Korean age, a baby is one at birth and gains a year on New Year's Day, so a Korean age can run one or two years ahead of the chronological figure. East Asian reckoning more broadly has counted from birth as year one. These are cultural conventions, not different math, and the calculator reports the standard chronological age.

Leap year edge cases#

A leap year adds February 29. If you were born on February 29, common years have no such date, so your birthday is usually marked on February 28 or March 1 depending on local rules. The day count is unaffected: the calculator still counts every real day between the two dates, including each February 29 that falls in the range.

Frequently asked questions#

How is age counted in most Western countries?#

By chronological age: the number of complete years from your birth date to today. You turn a year older on your birthday, and the count includes every leap day in between.

Can it give my age in days, hours and minutes?#

Yes. Enter a birth date and a reference date and the calculator returns the total in days, weeks, hours or minutes as well as years, months and days. For example, 36 years works out to roughly 13,148 to 13,149 days, depending on how many leap days the span includes.

How do I find the age difference between two people?#

Enter both birth dates. The gap between them is the same on any day, so the difference in years, months and days does not change as both people get older.

How are leap years handled?#

Automatically. Every February 29 inside the date range is counted as a real day, so the total days and the years, months and days output are both exact across leap years.

Can it count down to a future birthday?#

Yes. Set the reference date to the upcoming birthday and the result is the number of days until then, which is useful for planning an event weeks or months ahead.