The cost of a recreational vehicle (RV) may require you to take out a loan to pay for it over time. Even if you can afford to pay cash for your RV, some people choose to take out a loan because your RV may qualify as a second home, meaning that you can take a tax deduction for the interest that you pay on your RV loan. In order to calculate the monthly payment for your loan, you need to determine how much you are borrowing, what interest rate you will pay, and how long you will take to repay the loan.

Determine how much you need to borrow to purchase your RV. When considering how much to borrow, keep in mind that you will usually need to make a 20 percent down payment on the vehicle.

Determine the interest rate you will pay. The interest rate will depend on how much you are borrowing, the size and term of your loan, and your credit score.

Determine the length of your loan. Most RV loans range from five years for smaller loans to as long as 20 years.

Calculate the monthly payment for your RV loan using an online calculator (see resources) or the following formula where B is the amount borrowed, R is the annual interest rate, and P is the number of payments you have to make: Monthly Payment = B * (R/12 + ( R/12 / ((1+R/12)^P - 1))) For example, if you borrowed $50,000 at 7 percent interest for a 10-year loan, your monthly payment would be equal to $580.54.