Leap year checker
A leap year adds a 29th day to February so the calendar stays in step with Earth's trip around the Sun. This checker tells you whether a year is a leap year and how many days it has. It helps with homework, date code and planning around February 29.
- Runs in your browser
- Free, no account needed
- Copy or download the result
Result
Example
2000
2000 is a leap year. February has 29 days; the year has 366 days.
How to use the leap year checker
- Type a whole year from 1 to 9999, such as 2000.
- Press Run to check the year.
- Read whether it is a leap year, the days in February and the days in the year.
- Use Copy result or Download if you need to save it.
How it works
Years divisible by 4 are leap years.
Century years like 1900 are not leap years unless they are also divisible by 400, like 2000.
The rule is the Gregorian one, applied to all years from 1 to 9999, including years before the calendar was adopted.
Decimals, negative years and years above 9999 are rejected.
Everything runs in your browser. Your input is not uploaded or stored.
Questions and answers
How do you know if a year is a leap year?
It must be divisible by 4. If it is a century year ending in 00, it must also be divisible by 400.
Was 1900 a leap year?
No. 1900 is divisible by 100 but not by 400, so February 1900 had 28 days.
Is 2000 a leap year?
Yes. 2000 is divisible by 400, so it had 366 days.
How many days are in a leap year?
A leap year has 366 days, with 29 days in February. Other years have 365.