Leap Year Calculator
Check whether any year is a leap year — with a step-by-step rule breakdown and the nearest leap years on either side.
The Gregorian leap year rule
The Earth takes about 365.2422 days to orbit the Sun. A plain 365-day calendar drifts roughly one day every four years, shifting seasons slowly out of alignment with the months. The Gregorian calendar corrects this with a three-part rule:
- A year divisible by 4 is a leap year.
- Exception: years divisible by 100 are not leap years.
- Exception to the exception: years divisible by 400 are leap years.
This gives an average year length of exactly 365.2425 days — close enough that the calendar only drifts one day in about 3,300 years.
Frequently asked questions
Is 2026 a leap year?
No. 2026 is not divisible by 4, so it is a regular year with 365 days. The next leap year is 2028.
What makes a year a leap year?
A year is a leap year if it is divisible by 4 — except that years divisible by 100 are not leap years, unless they are also divisible by 400. So 2000 was a leap year, but 1900 was not.
Why do we need leap years?
The Earth takes approximately 365.2422 days to orbit the Sun. Without leap years, the calendar would drift about one day every four years. Adding a day every four years (with century corrections) keeps the calendar aligned with the seasons over centuries.
What happens to people born on February 29?
People born on February 29 (leap day) are sometimes called leaplings. In non-leap years they typically celebrate on February 28 or March 1, depending on local convention. Legally, many jurisdictions treat March 1 as their official birthday in non-leap years.
How often do leap years occur?
Leap years occur roughly every 4 years, but the century rule means that 3 out of every 400 years are skipped (1700, 1800, and 1900 were not leap years; 2100 will not be). The average calendar year is therefore 365.2425 days, very close to the astronomical year.