Leap Year Calculator
Check whether a year is a leap year and how many days it has. Enter your values, click Calculate, and get the full result with its breakdown — everything is processed on your device, nothing is sent to a server.
All calculations run in your browser. Your data is never sent to our servers.
Example
Example Input
2000
Example Output
leap year (366 days)
How to Use
- 1Fill in each input field with the values you want to compute.
- 2If there are choices (units, mode, operation), pick what you need.
- 3Click the Calculate button (or press Ctrl+Enter).
- 4The main result and its breakdown appear in the Result area. Click Copy to copy it.
About the Leap Year Calculator
The Leap Year Calculator determines whether a year is a leap year using the Gregorian rule: divisible by 4, except divisible by 100 but not 400. A leap year has 366 days (Feb 29).
Useful for calendar calculations and date programming.
FAQ
Is this Leap Year Calculator accurate?
Yes. It uses standard formulas and runs directly in your browser at full JavaScript precision (plus BigInt/decimal.js for large numbers where needed).
Is my data sent to a server?
No. All calculations happen entirely on your device. No values are sent to or stored on our servers.