A solar year is about 365.2422 days, so the Gregorian calendar adds a 29 February in 97 of every 400 years: every fourth year, except century years not divisible by 400. 2000 was a leap year; 1900 and 2100 are not.
How to use the Leap Year Calculator
- Year
- Count from year
- Count to year
Results update as you type, and every field accepts the units shown in its menu.
How it works
Enter a year, and optionally a range of years to count leap years in.
Upcoming leap years
2028, 2032, 2036, 2040, 2044, 2048, 2052, 2056, 2060, 2064, 2068, 2072, 2076, 2080, 2084, 2088, 2092, 2096, then 2104 (2100 is skipped).
Inputs explained
| Field | What to enter |
|---|---|
| Year | A number |
| Count from year | A number |
| Count to year | A number |
Formula
Leap year if divisible by 4, except century years, which must be divisible by 400
Leap years up to y: L(y) = ⌊y/4⌋ − ⌊y/100⌋ + ⌊y/400⌋
Worked example
Inputs: Year: 2,026; Count from year: 2,000; Count to year: 2,100.
Results: Is it a leap year? = No – 365 days; Next leap year = 2028; Previous leap year = 2024; 29 February falls on a = Tuesday; Leap years in the range = 25.
Frequently asked questions
Is 2028 a leap year?
Yes, because it is divisible by 4 and not a century year.
Why isn't 2100 a leap year?
Century years are leap years only when divisible by 400.
How often is there a leap year?
Usually every 4 years, 97 times every 400 years.