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Leap Year Calculator

Check whether a year is a leap year, see the rule that decided it, and list nearby leap years.

Enter a year to check.

Calculated in your browser. Nothing you enter is uploaded.

How to check whether a year is a leap year

  1. Enter a year

    Type any whole-number year, including years far in the past or far in the future.

  2. Read the answer

    The tool states plainly whether the year is a leap year and names the exact rule that decided it.

  3. Check the day counts

    See how many days February and the whole year have for the year you entered.

  4. Browse nearby leap years

    The next and previous 10 leap years are listed so you can see the pattern around your year.

Why use this tool

A plain yes or no answer

States clearly whether the year you entered is a leap year, with no ambiguity for century years.

Shows the exact rule

Every answer names which rule decided it: divisible by 4, not divisible by 100, or divisible by 400 despite that.

Day counts included

See both the number of days in February and the total number of days in the year at a glance.

Next and previous 10 leap years

Two lists show the 10 leap years before and the 10 leap years after the year you entered, so the four-year pattern and its century-year exceptions are easy to see.

Works far outside the present

Years far in the past or far in the future are handled with the same rule, since the leap year rule does not change over time.

One-click copy

Copy answer turns the result into a short line of plain text.

About this tool

A year is a leap year if it is divisible by 4, unless it is also divisible by 100, in which case it is not a leap year, unless it is additionally divisible by 400, in which case it is a leap year after all. This tool applies that exact rule to the year you enter and states the answer plainly, along with which part of the rule actually decided it, since the century-year exception is the part most people get wrong. The year 2000 was a leap year because it is divisible by 400, while 1900 was not, because it is divisible by 100 but not by 400.

Alongside the answer, the tool shows how many days February has that year, 28 or 29, and how many days the whole year has, 365 or 366. Two lists then show the 10 leap years immediately before and the 10 immediately after the year you entered, which makes the usual four-year spacing and the occasional century-year exception easy to see at a glance. The rule applies the same way to any whole-number year, so a date far in the past or centuries into the future is handled correctly, not just years within an ordinary calendar's range.

The whole check runs in your browser, so the year you enter is never uploaded or stored. To count the days between a date in a leap year and another date, use the date difference calculator; to find the day of the week a specific date fell on, use the day of the week calculator; and to work out an exact age across leap years, use the age calculator.

Frequently asked questions

What is the rule for a leap year?
A year is a leap year if it is divisible by 4, except that a year divisible by 100 is not a leap year, unless that year is also divisible by 400, in which case it is a leap year after all.
Why was the year 2000 a leap year but 1900 was not?
2000 is divisible by 400, so it is a leap year despite also being divisible by 100. 1900 is divisible by 100 but not by 400, so the century-year exception applies and it was not a leap year.
How many days does a leap year have?
A leap year has 366 days instead of the usual 365, with the extra day added as 29 February.
Can I check years far in the past or future?
Yes. The same divisibility rule applies to any whole-number year, so years centuries in the past or future are checked the same way as recent ones.
Is the year I enter stored anywhere?
No. The check runs entirely in your browser, and the year you enter is never uploaded or logged.

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