Leap Year Checker & Calendar Tool
Verify if a year is a leap year. Enter any year below to read the mathematical divisibility steps.
Processed locally in your browser — nothing is uploaded.
How to Use
- Enter a calendar year.
- Click Check Year.
- Review leap year results and formulas.
FAQ
What is the rule for leap years?
A year is a leap year if divisible by 4, except when divisible by 100 unless also divisible by 400.
Why do we have leap years?
To align our calendar year with the Earth’s astronomical revolution, which takes roughly 365.24 days.