What is the Birthday Calculator?
Find the weekday you were born on, your next birthday and how old you will turn.
Enter date of birth and the Birthday Calculator returns born on a, next birthday, you will turn, days to go and days lived so far. Results update as you type, and nothing you enter leaves your device.
How it is calculated
Next birthday = the next date with the same day and month as your date of birth
How to use it
- Enter date of birth.
- Read born on a in the results panel. It updates as you type.
- Change any value to compare scenarios, or use Share to send the result as a link.
Worked example
Common questions
What formula does the Birthday Calculator use?
It uses: Next birthday = the next date with the same day and month as your date of birth.
What do I need to use the Birthday Calculator?
You need date of birth. Sensible starting values are filled in so you can see how it works straight away.
Is the Birthday Calculator free, and is my data stored?
It is free with no sign-up. The calculation runs in your browser, so the values you enter are not sent to or stored on our server.