How do I check if a year is a leap year?

A year is a leap year if: (1) it is divisible by 4, AND (2) it is NOT a century year (divisible by 100), OR (3) it IS divisible by 400. In short: year % 4 == 0 AND (year % 100 != 0 OR year % 400 == 0).

When is the next leap year?

The next leap years are 2028, 2032, 2036, 2040, and 2044. Leap years occur every 4 years except for century years not divisible by 400.

Was 2024 a leap year?

Yes, 2024 was a leap year. It is divisible by 4 (2024 ÷ 4 = 506) and is not a century year, so it qualifies. February 29, 2024 existed.

Why was 1900 not a leap year but 2000 was?

Both 1900 and 2000 are divisible by 100 (century years), triggering the century exception. But 2000 is also divisible by 400 (2000 ÷ 400 = 5), which overrides the exception. 1900 ÷ 400 = 4.75, so 1900 was NOT a leap year.

How many leap years are in a century?

There are 24 or 25 leap years per century. In most 100-year periods there are 24 (the century year is skipped). In centuries divisible by 400 (like 1600–1700, 1900–2000, 2300–2400), there are 25 because the century year itself is a leap year.

What is a leapling or leap day baby?

A leapling (or leap day baby) is someone born on February 29. They only have a 'real' birthday every 4 years. In common years, they typically celebrate on February 28 or March 1 depending on local laws and personal preference.

Leap Year Checker

A leap year occurs when an extra day (February 29) is added to the calendar to keep it synchronized with Earth's orbit around the Sun. The Gregorian calendar uses a three-part rule: a year is a leap year if it is divisible by 4, except for century years (ending in 00), which must be divisible by 400. This is why 2000 was a leap year but 1900 was not. Our leap year checker explains exactly which rule applies to any year you enter, helps you find the next upcoming leap year, browse past leap years, and list every leap year between two dates.

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calendar_today Updated: April 2026

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Enter a Year

Quick:

calendar_month Upcoming Leap Years

2024 ✓ Was a leap year

2028 ✓ Next leap year

2032 ✓ Leap year

2036 ✓ Leap year

2040 ✓ Leap year

2044 ✓ Leap year

2096 ✓ Leap year

2100 ✗ NOT a leap year

rule The 3-Part Rule

Divisible by 4

2024 ÷ 4 = 506 ✓ — base rule

Except century years

1900 ÷ 100 = 19 ✗ — exception

Unless divisible by 400

2000 ÷ 400 = 5 ✓ — override!

(y%4==0 && y%100!=0)
|| y%400==0

lightbulb Quick Facts

•Leap year = 366 days (extra Feb 29)
•Earth's year ≈ 365.2425 days
•97 leap years every 400 years
•2100, 2200, 2300 are NOT leap years
•Next 400-year leap: 2400

The Formula

The Gregorian calendar corrects for the fact that Earth takes approximately 365.2425 days to orbit the Sun. Adding one day every 4 years slightly overcorrects, so century years (divisible by 100) skip the leap day, except every 400 years when the correction is needed again.

Leap year if: (year % 4 == 0 AND year % 100 ≠ 0) OR (year % 400 == 0)

lightbulb Variables Explained

tips_and_updates Pro Tips

The year 2000 was a leap year because it is divisible by 400 — this confused many early computers.

Leap years always fall on even years ending in 0, 4, 8, or (sometimes) 2 and 6.

February 29 birthdays are celebrated on February 28 or March 1 in non-leap years depending on local tradition.

The next century-year exception is 2100 — NOT a leap year despite being 4 years after 2096.

Adding a leap day every 4 years corrects for ~6 hours/year Earth takes beyond 365 days.

Frequently Asked Questions

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Leap Year Checker

calendar_month Upcoming Leap Years

rule The 3-Part Rule

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The Formula

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Frequently Asked Questions

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