## How to Calculate Leap Year Between Two Years

Calculating leap years between two years can be useful for a variety of reasons, such as for planning travel or for calculating interest on loans. While the concept of a leap year may seem simple, it can be tricky to calculate the number of leap years between two years. In this guide, we’ll show you how to calculate leap years between two years using the Gregorian calendar.

### Understand the concept of a leap year

A leap year is a calendar year that contains an additional day to keep the calendar year synchronized with the astronomical year. In the Gregorian calendar, a leap year occurs every four years, except for years that are divisible by 100 and not by 400. For example, the year 2000 was a leap year, but 1900 was not.

### Determine the starting and ending years

Before you can calculate leap years between two years, you need to determine the starting and ending years. For this example, let’s say we want to calculate leap years between the years 2000 and 2020.

### Identify the leap years in the starting year

To identify the leap years in the starting year, divide the starting year by 4. If the remainder is 0, the starting year is a leap year. In our example, 2000 is divisible by 4, so it is a leap year.

### Identify the leap years between the starting and ending years

To identify the leap years between the starting and ending years, you need to go year by year and check if it is a leap year. If the year is divisible by 4 and not divisible by 100, it is a leap year. If the year is divisible by 100 and also divisible by 400, it is a leap year. For our example, the leap years between 2000 and 2020 are 2000, 2004, 2008, 2012, 2016, and 2020.

### Count the number of leap years

To calculate the number of leap years between the starting and ending years, simply count the number of leap years you identified in step 4. In our example, there are six leap years between 2000 and 2020.

### Calculate the number of days in the leap years

To calculate the number of days in the leap years, simply multiply the number of leap years by 366 (the number of days in a leap year). In our example, there are six leap years, so the total number of days in the leap years is 6 x 366 = 2196.

### Calculate the number of days in the non-leap years

To calculate the number of days in the non-leap years, subtract the number of leap years from the total number of years between the starting and ending years, and then multiply by 365 (the number of days in a non-leap year). In our example, there are 20 years between 2000 and 2020, and six of those years are leap years. So, the total number of non-leap years is 20 - 6 = 14, and the total number of days in the non-leap years is 14 x 365 = 5110.

### Calculate the total number of days

To calculate the total number of days between the starting and ending years, add the number of days in the leap years (from step 6) to the number of days in the non-leap years (from step 7). In our example, the total number of days between 2000 and 2020 is 2196 + 5110 = 7306.

### Convert the total number of days to years, months, and days

To convert the total number of days to years, months, and days, you need to use a calendar. In our example, there are 7306 days between 2000 and 2020. First, divide the total number of days by the number of days in a year (365.2425) to get the number of years. 7306 ÷ 365.2425 = 20.0077 years. This means that the two years are 20 years and approximately 0.0077 years (or 2.8161 days) apart. To calculate the number of months, multiply the decimal portion of the years by 12. 0.0077 x 12 = 0.0924 months. This means that the two years are approximately 0.0924 months (or 2.8 days) apart. To calculate the number of days, multiply the decimal portion of the months by the number of days in a month (usually 30). 0.8 x 30 = 2.77 days. This means that the two years are approximately 20 years, 0 months, and 2.77 days apart.

### Check your work

To check your work, you can use a calendar to count the number of days between the starting and ending years. In our example, counting the days between January 1, 2000 and December 31, 2020 gives you a total of 7305 days, which is close to our calculated total of 7306 days.

### Optional: Use an online calculator

If you don’t want to do the calculations by hand, there are many online calculators that can help you calculate the number of leap years between two years. Simply enter the starting and ending years, and the calculator will do the rest.

### Optional: Use a spreadsheet program

If you prefer to use a spreadsheet program like Microsoft Excel, you can create a formula that calculates the number of leap years between two years. There are many tutorials available online that can guide you through the process.

### Tips

Remember that a leap year occurs every four years, except for years that are divisible by 100 and not by 400.

### Warnings

Be careful when doing calculations with dates, as mistakes can be costly. Double-check your work and use a calculator or spreadsheet program if necessary.

### Things You’ll Need

- A calendar
- A calculator or spreadsheet program (optional)

### Conclusion

Calculating leap years between two years can be a bit tricky, but with this guide, you should be able to do it with ease. Remember to double-check your work and be careful when doing calculations with dates. With practice, you’ll be able to do these calculations quickly and accurately.