Leap Year Checker
Check whether a year is a leap year, and how many days it has. A single, precise answer.
Leap year check
How it works
A leap year adds February 29 so the calendar stays aligned with the seasons. The rule: a year is a leap year if it divides evenly by 4 — except century years, which must divide evenly by 400.
Examples
- 2024 is a leap year (366 days).
- 1900 is not a leap year (365 days), because it divides by 100 but not 400.
- 2000 is a leap year, because it divides by 400.
Need birth dates and ages across one? Try the Age Calculator.
Frequently asked questions
How is a leap year decided?
A year is a leap year if it is divisible by 4 — except centuries, which must be divisible by 400. So 2024 is a leap year, 1900 is not, and 2000 is.
How many days does a leap year have?
366. The extra day is February 29.
Which calendar does this use?
The Gregorian calendar, which is the calendar in common use in most of the world.
Why would someone born on February 29 need this?
A February 29 birthday is a leap-day case. In years without February 29, that birthday is observed on February 28.