Free Online Leap Year Checker

What is a Leap Year?

A leap year is a calendar year that contains an additional day added to keep the calendar year synchronized with the astronomical or seasonal year. Because the Earth's orbit around the Sun takes approximately 365.2425 days, a "common year" of 365 days slowly drifts out of sync with the seasons. By inserting an extra day—February 29th—roughly every four years, this drift is corrected. Our online leap year calculator applies these rules.

How to Determine if a Year is a Leap Year (The Rules)

The rules for determining a leap year are as follows:

• The year must be evenly divisible by 4.
• However, if the year can also be evenly divisible by 100, it is NOT a leap year, UNLESS...
• The year is also evenly divisible by 400. Then it IS a leap year.

For example, the year 2000 was a leap year (divisible by 4, 100, and 400). The year 1900 was not a leap year (divisible by 4 and 100, but not by 400). The year 2024 is a leap year (divisible by 4, not by 100). Use our free leap year test to check any year.

Why Use Our Free Leap Year Checker?

• Accurate Calculation: Applies the correct Gregorian calendar rules for leap years.
• Instant Results: Quickly find out if a year is a leap year or not.
• Easy to Use: Simply enter the year and click check.
• Educational: Understand why certain years are leap years.
• Useful for Planning: Helpful for scheduling or historical research.
• Downloadable Result: Save the result of your check.

Wondering "Is 2024 a leap year?" or about any other year? This tool gives you a quick answer.