Leap Year Checker
A leap year adds an extra day (February 29) to keep the calendar aligned with Earth’s orbit. Toolverge applies the Gregorian rule: a year is a leap year if divisible by 4, except century years (divisible by 100), which are leap years only if also divisible by 400 — so 2000 was a leap year but 1900 was not. The tool also lists every leap year within a chosen range, capped at 1,000 years per query.
How it works
- Enter a year to check.
- Read whether it is a leap year and which rule applied.
- Scroll down to list every leap year within a start/end range.
Formula Leap year if (year % 4 == 0 and year % 100 != 0) or (year % 400 == 0)
Frequently asked questions
What makes a year a leap year?
It is divisible by 4, except century years, which must also be divisible by 400.
Why was 1900 not a leap year but 2000 was?
1900 is divisible by 100 but not 400, so it is excluded. 2000 is divisible by 400, so the century exception does not apply and it is a leap year.
How many days does February have in a leap year?
29 days, instead of the usual 28.
Can I list all leap years in a range?
Yes, use the range section below the main result; ranges are capped at 1,000 years per query.
Is this data stored?
No. The calculation runs in your browser. Toolverge does not send this year to the Java API.