Why Use This Tool?
Most people know 'divisible by four means leap year' — and most people are subtly wrong. Century years break the rule: 1900 wasn't a leap year, 2000 was. This checker applies the full Gregorian rule to any year and tells you exactly why it lands the way it does.
You also get the year's total days, whether February 29 exists in it, and the surrounding leap years — handy for date arithmetic, warranty math, or settling office bets.
How It Works
- Type any year from 1 to 9999.
- Click check — the result appears instantly with the reasoning.
- See the next three and previous two leap years for planning.
Frequently Asked Questions
Is this a leap year?
Type the year above and the checker answers instantly, with the specific rule that decides it — the divisible-by-4 rule, the century exception, or the 400 exception.
Why wasn't 1900 a leap year?
Century years must be divisible by 400 to count. 1900 divides by 100 but not 400, so it was a common year; 2000 divided by 400, so it wasn't skipped.
When is the next leap year?
The result card lists the next three leap years after your input, so planning a February 29 event is a scroll away.
Tips & Things to Watch
- Remember the full rule: /4 yes, /100 no, /400 yes again.
- Leap years matter in date diffs — use the Date Difference calculator for exact counts.
- The Gregorian rule repeats every 400 years — 2000 and 2400 behave identically.