A leap year has 366 days instead of 365, with an extra day on 29 February, and it occurs in years divisible by 4 — except century years, which must also be divisible by 400. This free online Leap Year Calculator tells you instantly whether any given year is a leap year.
Leap Year Calculator
Using the online Leap Year Calculator is very straightforward. Just enter a year and we'll tell you if that year is a leap year or not.Example Leap Year Calculations
Information, facts and tips regarding the Leap Year Calculator and leap year calculation
1. What leap year is? Why do we have it?
Leap year is a special calendar year that contains an additional day and has 366 days. Leap year is used to keep the calendar year synchronized with the astronomical year. Using the leap ‘technique’ we can keep the Gregorian calendar in alignment with Earth’s revolutions around the Sun.
2. Why is there a leap year (almost) every 4 years?
As explained in more detail the Gregorian calendar has exactly 365 days in a year but the Earth takes approximately 365.242189 days to circle once around the Sun. So that’s why we always adding one extra day in the calendar every four years compensates for the fact that a period of 365 days is shorter than a tropical year by almost 6 hours.
3. Why is there a leap day?
The extra day during leap years is called a leap day and it’s on February 29. February was chosen because it’s the shortest month.
4. How is the Leap Year Calculator works? How to calculate leap years?
We use the following formula to calculate a leap year. A year is a leap year if meet the following requirements:
• The year can be evenly divided by 4.
• It’s not a leap year if can be evenly divided by 100 unless the year can be exactly divided by 400.
The second rule means that years 1200, 1600, 2000, 2400, and 2800 are leap years, while 1700, 1800, 1900, 2100, 2200, 2300, 2500, 2600, and 2700 are not leap years (in spite of each can be divided by 4).
5. How often are leap years?
According to the leap year calculation described above, almost every 4 years is a leap year.
6. Which are leap years?
Leap years between 1900 and 2100 ((1900 and 2100 are not leap years):
1904, 1908, 1912, 1916, 1920, 1924, 1928, 1932, 1936, 1940, 1944, 1948, 1952, 1956, 1960, 1964, 1968, 1972, 1976, 1980, 1984, 1988, 1992, 1996, 2000, 2004, 2008, 2012, 2016, 2020, 2024, 2028, 2032, 2036, 2040, 2044, 2048, 2052, 2056, 2060, 2064, 2068, 2072, 2076, 2080, 2084, 2088, 2092, 2096
Frequently asked questions
How do I know if a year is a leap year?
A year is a leap year if it is divisible by 4, except for century years, which must be divisible by 400. So 2024 and 2000 are leap years, but 1900 is not.
Why do we have leap years?
A solar year is about 365.24 days, so adding a day every four years keeps the calendar aligned with the seasons. Without it, dates would slowly drift.
Is 2100 a leap year?
No. Although 2100 is divisible by 4, it is a century year not divisible by 400, so it is not a leap year.
When is the next leap year?
Leap years occur every four years. Enter a year in the calculator to see whether it is one and find the next leap year after it.
What happens if you are born on 29 February?
People born on 29 February, sometimes called leaplings, officially celebrate on 28 February or 1 March in common years, but their true birthday returns every four years.