Age Calculator
Works out an exact age from a date of birth, today or on any other date.
Share sends a link that reopens these numbers. Copy details pastes the full breakdown as a list.
The formula
years and months: the most whole months from the birth date without passing the date days: what is left over
Months are always measured from the birth date, so a long run of short months cannot pull the day of the month down.
What to watch out for
Age is a count of calendar anniversaries, so years and months are not fixed lengths. The total in days is exact.
Frequently Asked Questions
How old is someone born on 29 February?
Here, their birthday is taken as 28 February in years without a 29th. Born on 29 February 2000, they are 1 year old on 28 February 2001. Some places use 1 March in law.
How many days old am I?
Count every day since your date of birth. Someone born on 1 January 2000 was 9,132 days old on 1 January 2025.
Can I find my age on a past or future date?
Yes. Change the second date to the one you need, such as an application deadline or the start of a school year.