Leap Year Calculator
Check if any year is a leap year and find nearby leap years.
📐 A year is a leap year if divisible by 4, except centuries (÷100) unless also divisible by 400.
A leap year has 366 days instead of 365, with February 29 added to keep the calendar aligned with Earth's orbit (which takes approximately 365.25 days). The leap year rule has an important exception — not every year divisible by 4 is a leap year. This calculator tells you whether any year is a leap year, finds the next and previous leap years, and lists all leap years in any range you specify.
📋 How to Use This Calculator
Enter any year to instantly see if it is a leap year, the reason (divisible by 4 but not 100, or divisible by 400), the next and previous leap years, and days in February. Use the range tool to list all leap years between two dates — useful for date difference calculations and financial calculations involving interest accrual over leap years.
💡 Key Facts & Information
Leap year rules: A year is a leap year if: (1) divisible by 4, AND (2) not divisible by 100, UNLESS (3) also divisible by 400. So: 2024 = leap (÷4 ✓, not ÷100 ✓). 1900 = not leap (÷100 ✓, not ÷400 ✗). 2000 = leap (÷400 ✓). 2100 = not leap (÷100 ✓, not ÷400 ✗). The rule corrects for the fact that Earth's orbit is 365.2422 days — the 400-year cycle of 97 leap years gives an average year length of 365.2425 days, accurate to within 1 day per 3,030 years. Next missed leap year: 2100. Last missed: 1900. Financial impact: bonds, loans with daily interest accrue one extra day of interest in leap years.