Leap Year Calculator
Enter any year below to instantly check whether it's a leap year.
How This Is Calculated
A year is a leap year if it's divisible by 4, unless it's also divisible by 100 — in which case it needs to be divisible by 400 too.
Worked example
Is 2024 a leap year?
2024 ÷ 4 = 506, with no remainder, and it's not a century year.
Yes, 2024 is a leap year.
Frequently Asked Questions
What is the rule for leap years?
A year is a leap year if it's divisible by 4, unless it's also divisible by 100 — in which case it's only a leap year if it's also divisible by 400. This extra rule keeps the calendar aligned with Earth's actual orbit, which is slightly less than 365.25 days.
Why was the year 2000 a leap year but 1900 wasn't?
1900 is divisible by 100 but not by 400, so the century exception makes it a regular year. 2000 is divisible by both 100 and 400, so the exception doesn't apply and it's a leap year.
How often do leap years occur?
On average, once every 4 years, except century years not divisible by 400 are skipped — so there are 97 leap years every 400 years instead of the 100 you'd get from the simple divisible-by-4 rule alone.
Related Calculators
- Date Difference Calculator — Date Calculators
- Days Since Calculator — Date Calculators
- Days Until Calculator — Date Calculators
- Add Days to Date Calculator — Date Calculators