Leap Year Checker
Check instantly whether a given year is a leap year and see how many days it has, using the standard Gregorian calendar rule.
Your results
Calculation breakdown
- Rule
- Divisible by 4, and (not divisible by 100 OR divisible by 400)
Worked example
2028 is divisible by 4 and not by 100, so it is a leap year with 366 days. 1900 was divisible by 100 but not 400, so it was not a leap year.
Assumptions
- Based on the standard Gregorian calendar rule used in Australia.
How this calculator works
Enter any calendar year to check whether it is a leap year under the Gregorian calendar rule and see the total number of days it contains. Leap years add an extra day, 29 February, roughly every four years to keep the calendar aligned with the Earth's orbit.
Frequently asked questions
What is the rule for a leap year?
A year is a leap year if it is divisible by 4, except century years, which must also be divisible by 400.
Is 2000 a leap year?
Yes, 2000 is a leap year because it is divisible by 400, unlike 1900 which was not a leap year.
How many leap years occur per century?
Typically 24 or 25 leap years occur per century under the Gregorian rule, depending on the century boundary.