Leap Year Calculator
Enter a year to instantly check whether it is a leap year, plus find the nearest leap years before and after it.
What this calculator does
The Leap Year Calculator tells you instantly whether any given year is a leap year, and shows you the closest leap years before and after it.
How the calculation works
A leap year adds one extra day, February 29th, to keep the calendar aligned with Earth’s orbit around the sun, which takes slightly more than 365 days. Under the standard Gregorian calendar rule, a year is a leap year if it is divisible by 4, unless it is also divisible by 100, in which case it is only a leap year if it is also divisible by 400. This is why 2000 was a leap year but 1900 and 2100 are not.
Understanding leap years is useful for calendar planning, scheduling recurring events, and general date arithmetic. This calculator is intended for everyday and educational reference.