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Leap Year Calculator

Learn if a year has an extra day, why it qualifies (or not), and explore leap years across any custom range.

Single Year Check

Try historic years (e.g., 1900, 2000) or future dates.

2026 is not a leap year.

Not divisible by 4 → common year.

Previous leap year: 2024 • Next leap year: 2028

Find Leap Years in a Range

Ranges can be as large as you like, but extremely wide spans may be best processed in a spreadsheet.

Leap years between 2026 and 2046:

2028, 2032, 2036, 2040, 2044

Show detailed reasoning for each year
2026Common yearNot divisible by 4 → common year.
2027Common yearNot divisible by 4 → common year.
2028Leap yearDivisible by 4 but not 100 → leap year.
2029Common yearNot divisible by 4 → common year.
2030Common yearNot divisible by 4 → common year.
2031Common yearNot divisible by 4 → common year.
2032Leap yearDivisible by 4 but not 100 → leap year.
2033Common yearNot divisible by 4 → common year.
2034Common yearNot divisible by 4 → common year.
2035Common yearNot divisible by 4 → common year.
2036Leap yearDivisible by 4 but not 100 → leap year.
2037Common yearNot divisible by 4 → common year.
2038Common yearNot divisible by 4 → common year.
2039Common yearNot divisible by 4 → common year.
2040Leap yearDivisible by 4 but not 100 → leap year.
2041Common yearNot divisible by 4 → common year.
2042Common yearNot divisible by 4 → common year.
2043Common yearNot divisible by 4 → common year.
2044Leap yearDivisible by 4 but not 100 → leap year.
2045Common yearNot divisible by 4 → common year.
2046Common yearNot divisible by 4 → common year.

How to Use This Calculator

1

Check a single year

Enter any year to instantly see if February has 29 days and understand the rule that applies.

2

Scan a full range

Set start/end years to list every leap year within the span. Great for planning events or scheduling projects.

3

Review the reasoning

Expand the detailed list to see which divisibility rule passes or fails for each year.

Formula

Leap Year if:

Year % 4 = 0

AND (Year % 100 ≠ 0 OR Year % 400 = 0)

Example: 2100 % 4 = 0 and 2100 % 100 = 0 but 2100 % 400 ≠ 0 → not a leap year. Meanwhile 2000 % 400 = 0 so 2000 is a leap year.

Where Leap Years Matter

Leap years keep our calendar aligned with Earth’s orbit—without them, seasons would slowly drift. Use this tool when planning anything tied to exact dates:

  • Schedule recurring events (e.g., annual conferences) without drifting weekdays.
  • Ensure payroll and subscription billing account for February 29.
  • Plan travel or education schedules that span multiple years.
  • Check birthdays for leap-day babies (February 29).

Frequently Asked Questions

Why isn’t every 4th year a leap year?

Centuries like 1900 skip the leap day unless divisible by 400. This correction keeps the calendar in sync with the solar year.

How often do we skip a leap year?

Every century year not divisible by 400 (e.g., 2100, 2200, 2300) is skipped. Year 2000 was leap because it met the 400 rule.

Can I check BCE years?

Gregorian rules technically apply from 1582 onward. For historical dates before then, calendars vary—use astronomical calculators for precision.

What about other calendars?

This tool focuses on the Gregorian calendar. Lunar or other systems have different leap rules.