Leap Year Checker
Check any year, and see exactly which rule made it a leap year (or not).
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How to check whether a year is a leap year
- Type a year, for example
2028. - See whether it’s a leap year and which rule decides it.
The rule
A year is a leap year if it's divisible by 4 — unless it's also divisible by 100, in which case it isn't — unless it's also divisible by 400, in which case it is after all. That last exception is why 2000 was a leap year but 1900 and 2100 are not: this three-tier rule keeps the Gregorian calendar's average year length within about 26 seconds of the actual solar year.
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Questions about leap years
How do I know if a year is a leap year?
It must divide by 4, except years that divide by 100, which must also divide by 400. So 2024 and 2000 were leap years, but 1900 wasn’t and 2100 won’t be.
When are the next leap years?
2028, 2032, 2036 and 2040. Every fourth year until 2100, which is not a leap year.
Why do we have leap years?
A year is about 365.2422 days, not 365. Adding 29 February most fourth years keeps the calendar in step with the seasons.
Was 2000 a leap year?
Yes. It divides by 100, which would normally rule it out, but it also divides by 400, which makes it a leap year.