📆 Leap Year Calculator
Is it a leap year? Get a yes/no for any year with the rule explained — plus the surrounding leap years and where the Julian calendar disagrees.
✗ 2026 is not a leap year
365 days — February has 28.
2026 is not divisible by 4 → common year.
Gregorian rule: divisible by 4, except centuries not divisible by 400. Computed locally.
How the leap year calculator works
The Gregorian rule has three parts: a year is a leap year if it is divisible by 4, except that century years are not leap years unless they are divisible by 400. So 2024 is leap, 1900 is not (divisible by 100 but not 400), and 2000 is (divisible by 400). This tool applies the rule, states which clause decided it, and shows the previous and next leap years — all computed instantly on your device.
The century exception is the whole point of the Gregorian reform. The older Julian calendar made every fourth year a leap year with no exception, which added slightly too many days and let the calendar drift against the seasons. The 400-year correction removes three leap days every four centuries, keeping the calendar aligned — which is why the Julian and Gregorian calendars disagree on years like 1700, 1800 and 1900.
Frequently asked questions
What makes a year a leap year?
Under the Gregorian calendar: it must be divisible by 4, but century years (divisible by 100) are only leap years if also divisible by 400. So 2024 and 2000 are leap years; 1900 and 2100 are not.
Why isn't 1900 a leap year but 2000 is?
Both are divisible by 4 and by 100, so the century rule applies. 2000 is also divisible by 400, so it stays a leap year; 1900 is not divisible by 400, so it becomes a common year. This 400-year correction is what the Gregorian reform added.
How often is a leap year?
Almost every four years — 97 times in every 400 years. Three century years per four centuries are skipped, which makes the average year 365.2425 days, very close to the true solar year.
Do other calendars have leap years?
Yes, but differently: the Julian calendar leaps every 4 years with no exception; the Hebrew and Chinese calendars add a whole leap month in some years; the Islamic calendar has leap days in a 30-year cycle. This calculator covers the Gregorian rule (and shows the Julian one for comparison).
Is February 29 a real birthday?
Yes — "leaplings" born on 29 February have a birthday only in leap years; in common years they typically observe it on 28 February or 1 March, depending on jurisdiction and preference.