Leap Year Calculator – Check If a Year Is a Leap Year
Use this free leap year calculator to check whether any year is a leap year. Enter a year and get an instant result. The tool follows the standard Gregorian calendar rules: divisible by 4, with exceptions for 100 and 400.
Leap Year Calculator
Check if a year is a leap year. Leap years follow the rule: divisible by 4, except centuries unless divisible by 400.
Leap year rules
- Divisible by 4 → usually a leap year
- Divisible by 100 → not a leap year (unless also divisible by 400)
- Divisible by 400 → leap year
Examples: 2024 (÷4) is a leap year. 1900 (÷100, not ÷400) is not. 2000 (÷400) is a leap year.
Understanding leap years and the Gregorian calendar
A leap year contains 366 days instead of the usual 365. The extra day is February 29. Leap years exist because the Earth takes approximately 365.25 days to orbit the Sun. If we used a fixed 365-day year, the calendar would drift by about one day every four years. Over centuries, that would push summer into December and winter into June in the Northern Hemisphere. Leap years correct this drift.
The Gregorian calendar, used in most of the world, defines leap years with three rules. First, a year divisible by 4 is a leap year. So 2020, 2024, and 2028 are leap years. Second, years divisible by 100 are not leap years, unless they are also divisible by 400. So 1900 and 2100 are not leap years, but 2000 is. This refinement keeps the calendar accurate over long periods.
Our leap year calculator applies these rules for any year you enter. It is useful for programming, date logic, scheduling, or simply satisfying curiosity. People born on February 29 celebrate their birthday on February 28 or March 1 in non-leap years. The next leap years are 2028, 2032, 2036, and so on.