How Do I Calculate Finance Charges?

With a little knowledge about the finance charges are calculated is always a good thing. Most lenders, as you know it, you can do for you, but can be useful to check the math itself, however, important to understand that what is here presented a basic procedure for calculating the costs of financing and your lender may use a more complicated method. There may be other problems with your loan, which can affect the cost.

The first thing to understand is that there are two basic parts to get a loan. The first edition will be the most important. This is the amount of money you borrow. The lender wants to make a profit for their services (lending money) to do what is called interest. Many variable interest rates simple. This article will examine simple interest calculations.

Treaties on simple interest, the amount of interest (in percentage) does not change throughout the term of the loan. This is often called flat rate or fixed interest rates.

The simple interest formula is as follows:

Interest = Principal × Rate × Time


Interest is the total amount of interest paid.

Principal is the amount lent or borrowed.

Rate is the percentage of the principal charged as interest each year.

To do your math, the rate must be expressed as a decimal, so percentages must be divided by 100. For example, if the rate is 18%, then use 18/100 or 0.18 in the formula.

Time is the time in years of the loan.

The simple interest formula is often abbreviated:

I = P R T

Simple interest math problems can be used for borrowing or for lending. The same formulas are used in both cases.

When money is borrowed, the total amount to be paid back equals the principal borrowed plus the interest charge:

Total repayments = principal + interest

Usually the money is paid back in regular installments, either monthly or weekly. To calculate the regular payment amount, you divide the total amount to be repaid by the number of months (or weeks) of the loan.

To convert the loan period, 'T', from years to months, you multiply it by 12. To convert 'T' to weeks, you multiply by 52, since there are 52 weeks in a year.

Here is an example problem to illustrate how this works.

Example:

A single mother purchases a used car by obtaining a simple interest loan. The car costs $1500, and the interest rate that she is being charged on the loan is 12%. The car loan is to be paid back in weekly installments over a period of 2 years. Here is how you answer these questions:

1. What is the amount of interest paid over the 2 years?

2. What is the total amount to be paid back?

3. What is the weekly payment amount?

You were given: principal: 'P' = $1500, interest rate: 'R' = 12% = 0.12, repayment time: 'T' = 2 years.

Step 1: Find the amount of interest paid.

Interest: 'I' = PRT

= 1500 × 0.12 × 2

= $360

Step 2: Find the total amount to be paid back.

Total repayments = principal + interest

= $1500 + $360

= $1860

Step 3: Calculate the weekly payment amount.

Weekly payment amount = total repayments divided by loan period, T, in weeks. In this case, $1860 divided by 104 weeks equals $17.88 per week.

Calculating simple finance charges is easy once you have done some practice with the formulas.