Leap Year Calculator
Check if any year is a leap year. Find the next and previous leap years instantly.
A leap year occurs every four years to keep our calendar aligned with Earth's orbit around the Sun. Because Earth actually takes approximately 365.2422 days to complete one orbit, our standard 365-day calendar would gradually drift out of sync with the astronomical seasons without periodic correction. The solution, introduced by Julius Caesar in 46 BC and refined by Pope Gregory XIII in 1582, is to add an extra day — February 29 — to certain years. However, the rules are not as simple as "every four years." Century years like 1900 are skipped unless they are also divisible by 400, which is why 2000 was a leap year but 1900 was not.
Our free leap year calculator lets you instantly check whether any year is a leap year. It shows the three divisibility rules applied step by step, identifies the next and previous leap years, counts down to the next February 29, and generates a list of all leap years within any range you choose. Whether you are planning around a February 29 birthday, working on historical research, or simply curious, this tool gives you the answer in milliseconds. All calculations run in your browser with no data sent to any server.
Leap Years in a Range
How to Check If a Year Is a Leap Year
Leap years are a fundamental part of how our calendar stays in sync with the Earth's orbit. Without them, the seasons would slowly drift through the calendar months over centuries. The Gregorian calendar, which most of the world uses today, includes a precise set of rules to determine which years get an extra day. While the basic rule — divisible by 4 — is widely known, the century-year exceptions catch many people off guard. Our leap year calculator applies all three rules instantly and shows you the step-by-step logic for any year you enter.
How to Use This Tool
- Enter a year — type any year from 1 to 9999 in the input field. The current year is pre-filled by default.
- Click Check Year — the result appears instantly, showing whether the year is a leap year with a clear visual indicator.
- Review the rule checker — below the result, the three divisibility rules are shown with pass/fail indicators so you can see exactly why the year is or is not a leap year.
- See nearby leap years — the result grid shows the previous and next leap years relative to the year you entered.
- Generate a range list — use the From and To fields to list all leap years in any range, such as 2020 to 2050.
How It Works — The Three Rules
The Gregorian calendar determines leap years using three rules applied in sequence. First, if a year is divisible by 4 it is a candidate for a leap year. Second, if the year is also divisible by 100 it is not a leap year — this corrects the slight over-compensation of the basic 4-year rule, since a year is actually 365.2422 days, not 365.25. Third, if the year is divisible by 400 it is a leap year after all — this adds back the small fraction lost by the century-year rule. The result is that in every 400-year cycle there are exactly 97 leap years, producing an average year length of 365.2425 days, which is extremely close to the true orbital period. Our calculator applies these three rules programmatically and displays each step so you can understand why any given year is or is not a leap year.
Frequently Asked Questions
Is 2026 a leap year?
No, 2026 is not a leap year. A year must be divisible by 4 to be a leap year, and 2026 divided by 4 gives 506.5, so it does not meet the first requirement. The most recent leap year was 2024, and the next one will be 2028. In 2026, February has 28 days as usual.
When is the next leap year?
The next leap year is 2028. After 2028, leap years continue every 4 years: 2032, 2036, 2040, 2044, and so on. The pattern is straightforward except at century boundaries — 2100 will not be a leap year (divisible by 100 but not 400), while 2400 will be (divisible by 400). You can use the range list feature on this page to see all upcoming leap years.
What are the three rules for leap years?
Rule 1: If the year is divisible by 4, it is a leap year. Rule 2: If the year is also divisible by 100, it is NOT a leap year. Rule 3: If the year is also divisible by 400, it IS a leap year. These three rules work together. For example, 2024 passes Rule 1 and is a leap year. 1900 passes Rule 1 but also matches Rule 2, so it is not a leap year. 2000 passes Rules 1 and 2 but also matches Rule 3, so it is a leap year.
Why do we need leap years?
Earth takes approximately 365.2422 days to orbit the Sun, but our calendar year has only 365 days. This means the calendar is about a quarter of a day short each year. Without correction, the calendar would drift by about 1 day every 4 years — or about 24 days per century. After several centuries, summer would arrive during what the calendar says is winter. Leap years add an extra day every 4 years (with century corrections) to keep the calendar aligned with the astronomical seasons.
What happens if you are born on February 29?
People born on February 29, sometimes called leaplings or leapers, have their actual birth date occur only once every 4 years. In non-leap years, most leaplings celebrate their birthday on either February 28 or March 1 — the choice is personal. For legal purposes, the rules vary by jurisdiction. In England and Wales, for example, a leapling is legally considered to reach the next year of age on March 1 in non-leap years. There are approximately 5 million leaplings worldwide.
Was 1900 a leap year?
No, 1900 was not a leap year. Although 1900 is divisible by 4, it is also divisible by 100 — and the century-year rule says that years divisible by 100 are not leap years unless they are also divisible by 400. Since 1900 is not divisible by 400 (1900 / 400 = 4.75), it was not a leap year. February 1900 had only 28 days. This is the same reason that 2100, 2200, and 2300 will not be leap years either.
How many leap years are in a century?
In any given 400-year cycle, there are exactly 97 leap years. This breaks down to 100 years divisible by 4, minus 4 century years (divisible by 100), plus 1 year divisible by 400. For a single century, the count is typically 24 or 25 depending on whether that century includes a year divisible by 400. For example, the 21st century (2001-2100) has 24 leap years because 2100 is not a leap year, while the 20th century (1901-2000) had 25 because 2000 was a leap year.
