MMaxTools

Leap Year Calculator

Check if any year is a leap year and see the next leap years coming up.

The Leap Year Calculator instantly answers whether any given year is a leap year and explains why. It applies the official Gregorian rule — divisible by 4, except century years unless also divisible by 400 — and reports the verdict, the number of days in the year, and whether February has 29 days.

Leap years exist because a real solar year is about 365.2422 days, not exactly 365. Adding a day every four years overshoots slightly, which is why century years like 1900 and 2100 skip the leap day while 2000 — divisible by 400 — kept it. Understanding the rule settles date-math arguments, age calculations and any code that assumes February's length.

The tool also lists the next five leap years after the one you check, so you can see the cycle ahead. The same rule is used across this site's date calculators, keeping every age and day count consistent.

Leap year

Yes ✅

2,028 has 366 days

Next leap years

2032, 2036, 2040, 2044, 2048

following 2028-style 4-year cycle

February

Feb 29 exists

leap day added

Gregorian rule: a year is a leap year if it is divisible by 4 — except century years, which must also be divisible by 400. So 2000 was a leap year but 1900 and 2100 are not.

How to use the Leap Year Calculator

  1. Enter the year you want to check (1–9999).
  2. Read whether it is a leap year and how many days it has.
  3. Check whether February 29 exists that year.
  4. See the next five leap years for planning ahead.
  5. Probe interesting cases: 2000 (leap), 1900 (not), 2100 (not).

Frequently asked questions

What is the leap year rule?

A year is a leap year if it is divisible by 4 — except century years (ending in 00), which are leap years only if also divisible by 400. So 2028 is a leap year, 2100 is not, and 2400 will be.

Why do we need leap years at all?

The Earth takes about 365.2422 days to orbit the Sun. A 365-day calendar drifts almost a quarter day per year, pushing seasons backwards over centuries. The leap-day system (and the century exception) keeps the calendar aligned with the seasons to within about a day every 3,000 years.

When is the next leap year?

The calculator lists the next five leap years after any year you enter. For the current decade: 2028 is the next leap year after 2024, followed by 2032, 2036 and 2040.

What happens to February 29 birthdays in non-leap years?

People born on February 29 (leaplings) usually celebrate on February 28 or March 1 in common years. Legally and in most software, February 28 is treated as the birthday — this site's date tools use February 28 in common years for countdowns.