Toolstia / leap year checker
Leap year checker
Type a year to see whether it is a leap year, how many days it has and why. You can also list every leap year in a range of years.
Leap years in a range
11 leap years: 2000, 2004, 2008, 2012, 2016, 2020, 2024, 2028, 2032, 2036, 2040
A year is a leap year if it is divisible by 4, except years divisible by 100 that are not also divisible by 400. This is the rule of the Gregorian calendar.
How it works
- Enter a year.
- Read the answer and the reason.
- Use the range box to list leap years between two years.
The rule
A year is a leap year if it can be divided by 4. The exception is a year divisible by 100, which is not a leap year unless it is also divisible by 400.
Examples
2024 is a leap year. 1900 was not, because it is divisible by 100 but not by 400. 2000 was, because it is divisible by 400.
Why leap years exist
A solar year is about 365.2425 days long. An extra day about every four years keeps the calendar in step with the seasons.
Calendar
These rules are for the Gregorian calendar, which is used almost everywhere today.
Questions
Is 2100 a leap year?
No. It is divisible by 100 but not by 400.
How many days are in a leap year?
366, with 29 days in February.
Is my input stored?
Everything happens in your browser, and nothing you type is sent anywhere.