Calendar Year Checker
Leap Year Calculator
Check whether any year is a leap year, common year, or century exception. See days in the year, February 29 details, previous leap year, next leap year, and a simple nearby leap year timeline.
Enter a year to check leap year status.
Calculator
Check If a Year Is a Leap Year
Enter a year and the calculator will instantly apply the Gregorian leap year rule. You can also review nearby leap years in the visual chart.
Leap Year Result
--Enter Year
Add a year to see whether February 29 exists.
Leap Year Rule Check
Divisible by 4
--Century year?
--Divisible by 400
--Nearby Leap Year Timeline
Leap years near your selected yearThis calculator follows the standard Gregorian calendar rule used for most modern date calculations.
What Is a Leap Year Calculator?
A leap year calculator checks whether a selected year has 365 days or 366 days. In a leap year, February has 29 days instead of 28. This extra day is why leap years are important for calendars, birthdays, scheduling systems, education, payroll planning, anniversaries, and long date calculations.
Most people know that leap years happen every four years, but that is not the full rule. Some century years are exceptions. For example, 2000 was a leap year, but 1900 was not. This calculator handles those exceptions automatically, so you do not need to remember the full rule every time.
How the Leap Year Rule Works
A year is usually a leap year if it can be divided evenly by 4. However, if the year is also divisible by 100, it must be divisible by 400 to remain a leap year. This is the rule that explains why 2000 was a leap year but 1900 was not.
The extra rule exists because the calendar must stay close to the actual length of Earth's orbit. A simple every-four-years rule would add slightly too much time over centuries. The century exception corrects that long-term drift.
Why Leap Years Matter
Leap years affect more than calendars. They can influence birthday calculations, financial schedules, school calendars, software dates, event planning, and media production timelines. If a year has 366 days, date differences and annual totals can change.
For example, someone born on February 29 only has an exact calendar birthday in leap years. In other years, people may celebrate on February 28 or March 1 depending on personal preference or local rules.
If you are comparing two dates across many years, our Dating Age Calculator can help with age-related comparisons, while the Timecode to Frames Calculator is useful when time needs to be converted into frame counts for video work.
Leap Year Examples
Example 1: 2024
The year 2024 is divisible by 4 and is not a century year. Therefore, 2024 is a leap year and has 366 days.
Example 2: 1900
The year 1900 is divisible by 100 but not divisible by 400. Therefore, 1900 is not a leap year and has 365 days.
Example 3: 2000
The year 2000 is divisible by 400. Therefore, 2000 is a leap year, even though it is also a century year.
Example 4: 2100
The year 2100 is divisible by 100 but not by 400. That means 2100 is a common year, not a leap year.
Common Uses of a Leap Year Checker
Students use leap year calculators to learn calendar rules. Developers use them when testing date logic. Writers and planners use them to confirm whether February 29 exists in a specific year. Anyone working with annual schedules can benefit from checking whether the year has 365 or 366 days.
Leap year checks are also useful when reviewing long projects. A video editor may care about exact time and frame counts, which is why a tool like the Timecode to Frames Calculator can be helpful. For age-based date questions, the Dating Age Calculator gives a separate relationship-age view.
Leap Year Calculator FAQ
Is every 4th year a leap year?
Not always. Most years divisible by 4 are leap years, but century years must also be divisible by 400.
Why was 2000 a leap year?
Because 2000 is divisible by 400, it qualifies as a leap year under the Gregorian calendar rule.
Why was 1900 not a leap year?
Although 1900 is divisible by 4 and 100, it is not divisible by 400, so it was not a leap year.
How many days are in February during a leap year?
February has 29 days in a leap year.
How many days are in a common year?
A common year has 365 days.
Can I check future years?
Yes. Enter any future year and the calculator will apply the same leap year rule.