Leap Year Calculator
Check if any year is a leap year, find upcoming and past leap years, see all leap years in a range, and count down to the next February 29th.
The Leap Year Calculator is a free online tool designed to help you calculate and analyze check if any year is a leap year find the next and previous leap years see all leap years in a range and find days until the next february 29. Planning details accurately is crucial for making smart personal or financial decisions, and this calculator provides instant clarity with downloadable PDF reports.
This tool is built to benefit project managers, business professionals, students, and event planners who need to count calendar spans. Whether you are tracking contract deadlines, calculating ages, or scheduling international calls, this tool does the heavy lifting. By evaluating these key calculations, you can determine exactly how different inputs affect your results and align them with your direct planning requirements.
Before using this tool, make sure you have your details ready, such as your start and end dates or times, and toggle holiday or weekend filters depending on your calculation goals. This ensures the most accurate calculations.
How to Use the Leap Year Calculator
- Use the Check a Year tab to instantly find out if any specific year is a leap year. The calculator shows the exact reason based on the three-part Gregorian calendar rule and also shows nearby leap years for reference.
- Use the Leap Year Range tab to find all leap years between any two years. This is useful for historical research planning recurring events or satisfying curiosity about how many leap years fall in a century.
- The calculator also shows when the next February 29th is from today — useful for people born on February 29 who want to know when their actual birthday falls next.
- Download the free PDF with your complete leap year report.
Example Calculation
Scenario: Is the year 2100 a leap year? And how many leap years are there between 2020 and 2040?
- Tab 1 Input: Year = 2100
- Tab 2 Input: Start Year = 2020, End Year = 2040
Results: 2100 is NOT a leap year (divisible by 4 and 100, but NOT by 400). Range 2020–2040 contains 6 leap years: 2020, 2024, 2028, 2032, 2036, 2040.
Download the PDF to get a full leap year table for your range or a detailed fact sheet for the year you checked.
Frequently Asked Questions
What are the three rules for a leap year?
Under the Gregorian calendar, a year is a leap year if: (1) it is divisible by 4, AND (2) if it is divisible by 100, it must also be divisible by 400. So 2000 is a leap year, but 1900 and 2100 are not, even though they are divisible by 4.
Why do we have leap years?
A solar year is approximately 365.2422 days. Without leap years, our calendar would drift out of sync with the seasons by about one day every four years. Adding a 366th day every four years (with the century correction rule) keeps the calendar aligned with Earth's orbit.
Is 2100 a leap year?
No. Although 2100 is divisible by 4, it is also divisible by 100 but not by 400, so it is not a leap year. The last century year that was a leap year was 2000, and the next will be 2400.
What happens to people born on February 29?
People born on February 29 (leaplings) officially celebrate their birthday only every four years. In non-leap years, many observe their birthday on February 28 or March 1. This calculator shows the next upcoming February 29 and the days until it occurs.
How many leap years are there in a century?
In a typical 100-year period there are 24 or 25 leap years. In most centuries (e.g. 1900–2000) there are 24 because the century year itself is not a leap year. In centuries divisible by 400 (e.g. 1600–1700 or 2000–2100) there are 25.
Can I download a list of leap years as a PDF?
Yes. After using the Leap Year Range tab to find all leap years in your range, click Download Free PDF Report. The PDF lists every leap year found, the total count, the range summary, and a nearby leap year table — useful for historical research or calendar planning.