Example
2024 is a leap year. (366 days)
Leap Year Checker
Check if any year is a leap year instantly in your browser. Free online leap year calculator using the Gregorian rule — works for any year.
Enter the values below, then press Calculate (or press Enter). The calculator updates your results instantly. Try different values to see how your inputs change the outcome.
- Year to check — enter a numeric amount. A typical Year to check would be e.g. 2024.
- Review your results — the key output is highlighted, with supporting figures below.
Loading calculator…
Results
Result
| Detail | Value |
|---|---|
| Days in year | |
| Detail |
What is this calculator for?
Instantly determine whether a given year is a leap year using the standard Gregorian rule.
How to Use This Calculator
Enter the values below, then press Calculate (or press Enter). The calculator updates your results instantly. Try different values to see how your inputs change the outcome.
- Year to check — enter a numeric amount. A typical Year to check would be e.g. 2024.
- Review your results — the key output is highlighted, with supporting figures below.
What You'll Need
- Year to check
- a numeric amount range 1–9999 · required
About This Calculator
This leap year checker tells you whether any year is a leap year and how many days it has.
The Gregorian rule is: a year is a leap year if it is divisible by 4, unless it is also divisible by 100 — but it still is a leap year if it is divisible by 400. So 2024 and 2000 are leap years, while 1900 and 2100 are not.
That extra day appears on 29 February, giving the year 366 days. Checking runs instantly in your browser.
Worked Examples
Frequently Asked Questions
Why is 1900 not a leap year but 2000 is?
1900 is divisible by 100 but not by 400, so the century rule excludes it. 2000 is divisible by 400, so it remains a leap year.
Does this work for dates before the Gregorian calendar?
It applies the proleptic Gregorian rule for every year, which is the standard for most computations and date libraries.