Leap Year Checker
Check whether any year is a leap year, and see the next few leap years. Uses the standard Gregorian rules.
- Divisible by 4 → usually a leap year (e.g. 2024, 2028)
- Century years (…00) → leap only if divisible by 400
- 1900, 2100, 2200 → not leap · 1600, 2000, 2400 → leap
Calendar: proleptic Gregorian. Years before 1582 extend modern Gregorian rules backward and may not match the calendar used locally at the time.
Whole-number years only. A range may span at most 10,000 years.
Feb 29 weekday? Day of week · print month: Monthly calendar · age on birthday: Age calculator.
Check any leap year
Type a year to instantly see whether it is a leap year, the next ten leap years, and every leap year in a custom range — with the century rule explained and CSV export.
FAQ
What makes a year a leap year?
A year is a leap year if it is divisible by 4, except century years, which must be divisible by 400. So 2000 was a leap year but 1900 was not.
How many days are in a leap year?
366 days — February has 29 days instead of 28.
Why do we have leap years?
A solar year is about 365.2422 days, so an extra day every four years keeps the calendar aligned with the seasons.
Does this match historical calendars before 1582?
Not necessarily. The tool uses the proleptic Gregorian calendar, extending modern rules backward; places adopted the Gregorian calendar at different times.
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