More than a number of years
Most people only need their age in years, but forms, schools, sports leagues and legal rules often ask for exact age on a given date. This calculator gives years, months and days, and lets you pick the date you are measuring at.
It also shows how long you have lived in months, weeks, days and hours, and counts down to your next birthday, including the day of the week it falls on.
How the months and days are counted
Counting is done on the calendar, not by dividing days by 365. Between 15 May and 10 June, for example, is 26 days, because the days are counted from the month before the end date.
Months have different lengths, so any method gives slightly different answers at month boundaries. This one follows the common convention and is the one used for most official purposes.
Useful for
Checking eligibility dates, planning milestone birthdays, filling in forms that ask for age in months, working out a child’s age for growth charts, or satisfying curiosity about how many days you have been alive.
A worked example
Someone born on 15 May 1990 is, on 10 March 2024, 33 years, 9 months and 24 days old. Thirty-three years takes you to 15 May 2023, nine more months to 15 February 2024, and 24 days to 10 March. The same person has lived 12,353 days, which is about 1,764 weeks.
Questions people ask
How is exact age calculated?
Years, months and days are counted on the calendar from the birth date to the chosen date. If the day of the month has not yet reached the birth day, a month is held back and the days are counted from the previous month.
Can I find the age on a past or future date?
Yes. Set “Age at date” to any date. Leave it blank to use today’s date. This is useful for eligibility rules, such as being a certain age on a deadline.
What if I was born on 29 February?
In non-leap years the birthday is treated as 1 March, which is the convention in many places, including the UK. Some regions use 28 February, so check the rule that applies to you for legal purposes.
How many days old am I?
The total days figure counts every calendar day between the two dates, including leap days. Divide it by 7 for weeks.
Does it account for time zones?
No. It works with calendar dates only, so there is no hour-level difference. Your age changes at the start of your birthday in your own location.