Age and date calculator

Find your exact age from your date of birth, count the days between two dates and see which day you land on when you add days, weeks, months or years to a date.

Date of birth

Age on this date

Age—

Days lived—

Completed years, months and days are counted.

How to use

Pick a tab above the calculator and choose your dates. Results update straight away, there is no button to press.

Age: enter a date of birth. The second date is today by default, change it to see how old someone was or will be on another day. You also see the total number of days lived and how long until the next birthday.
Days between dates: enter a start and an end date to get the difference in years, months and days, the total number of days and weeks, and the number of working days. Tick the box if the end date should count too, for example for a holiday or a contract.
Add / subtract: choose a date, an amount and a unit to find a deadline, a due date or a date in the past. Example: 30 days after 1 March is 31 March.

All calculations run in your browser and your dates are not sent anywhere.

Frequently asked questions

How is my exact age calculated?

The calculator counts how many full years have passed since your date of birth, then the full months after that, then the remaining days. Someone born on 15 March 1990 is 34 years, 6 months and 10 days old on 25 September 2024.

How many days are there between two dates?

Subtract the earlier date from the later one. By default the start date counts and the end date does not, the same way you count nights in a hotel. If both days should count, for example for a leave request, tick "Include the end date" and one day is added.

Which days count as working days?

Monday to Friday. Saturdays and Sundays are left out. Public holidays differ by country and region, so they are not subtracted automatically. Remove them yourself if you need an exact count.

What happens to a 29 February birthday in other years?

In years that are not leap years the calculator treats 28 February as the birthday. Some countries officially use 1 March instead, so the next-birthday countdown may differ by one day.

What is 31 January plus one month?

February has no 31st day, so the result is the last day of February: the 28th, or the 29th in a leap year. This is the usual rule for contracts and payment due dates.