# Leap Year Calculator

URL: https://speedycalculator.com/calculators/everyday-life/leap-year/
Last updated: 2026-10-25

> The leap year calculator tells you whether a year is a leap year, the previous and next leap years, how many days the year has, and how many leap years fall between two years.

## Inputs

- Year
- Count from year
- Count to year

## Results

- Is it a leap year?
- Next leap year
- Previous leap year
- 29 February falls on a
- Leap years in the range

## 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⌋
```

## Explanation

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).

### Tips

- Check whether the end date should be included – event durations usually include it, elapsed time does not.
- Months have 28–31 days, so "one month" is counted by calendar date, not as 30 days.
- Use 24-hour time or set AM/PM carefully when entering clock times.
- Time zones and daylight-saving changes are not applied unless the calculator says so.

### Common mistakes to avoid

- Counting a 30-day month when a calendar month is meant (or the reverse).
- Forgetting leap years when counting days across February.
- Mixing decimal hours (7.5 h) with clock time (7:30).

### Inputs explained

FieldWhat to enterYearA numberCount from yearA numberCount to yearA number

## 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.

## FAQ

**Is 2028 a leap year?**
Yes – 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.

**What formula does the Leap Year Calculator use?**
Leap year if divisible by 4, except century years, which must be divisible by 400.