How does interest work on a car loan? 

how does interest work on a car

Lenders determine rates for auto loans using factors like the credit score, existing debt, and other aspects of the borrower’s financial history. Usually, borrowers with better credit are able to receive lower rates while borrowers with not-so-great credit may have to deal with higher rates. 

Purchasing a new car is a big financial decision, one that requires a significant amount of research. It’s always a good idea to gather all the information available on a topic before spending a large amount of money. Look into pricing for different vehicles, current car loan rates, required down payments, etc. 

When buying a car, it is likely you might be relying on a car loan rather than purchasing it outright. This will mean that you’ll be charged interest throughout the life of the loan until it is repaid in full. Because most car loans are installment loans, there will likely be a steady amount to pay on interest each month. You will want to have an in-depth understanding of how interest rates on a car loan work before signing any kind of contract agreement.

What Is An Auto Loan?

Auto loans are one of the most common ways of purchasing a vehicle for middle-class Americans. The average person does not have enough money to buy their car outright, so they get an auto loan. Vehicle loans are loans with monthly installments used for the express purpose of buying a car. 

The loan terms are set so that the loan balance plus interest is repaid within a specific period of time, typically between one and five years. Like mortgages, auto loans are a type of secured loan in which the equity of the car you buy is used as collateral. This means that if you repeatedly don’t make your monthly payments and default on the loan, your car could be repossessed by the lender. 

How Does Interest On Car Loans Work?

Every car loan will have an interest rate. Car loan interest can be thought of as the cost you pay for borrowing money so that you can purchase the vehicle. Lenders need to be paid for their services somehow, and a loan’s interest rate is the primary way they make a profit. 

However, the interest rate means that the amount you pay on your car loan will not equate to the price of the car. When repaying the auto loan, you need to pay the loan balance in full plus the interest that is accrued over the duration of the loan term.

How Is Interest Calculated?

Determining how your car loan interest is calculated might help you better understand how car loan interest works. How your car loan interest is calculated depends upon what type of interest rate you have on your loan. The percentage is not the only aspect of an interest rate that matters, but when and how often it is applied to the loan balance. 

The two most common types of interest rates used for car loans are simple interest and precomputed interest. 

Simple Interest Loan

Most vehicle loans are simple interest car loans. A simple interest loan has an annual percentage rate that is applied to the loan balance as it stands when each monthly payment is due. This means that the total interest paid can decrease if the loan is paid off earlier than the loan term dictates.

Simple interest loans have an amortization schedule, meaning each loan payment goes towards the loan amount and interest charges. You should be able to calculate the total amount of interest you will likely pay on the car loan if you follow the scheduled monthly payments by using the interest rate, the loan length, and the loan amount. 

Precomputed Interest Loan

Some auto loans have precomputed interest instead, which means that the interest is calculated upfront based on the loan amount. The interest charges will be added to the loan balance according to the loan term and will not change depending on how quickly you pay off the car loan. 

The monthly payments are not amortized on a precomputed interest loan, meaning that each car payment is not applied separately to both the interest and the balance. It is not as easy to decrease how much interest you pay with precomputed interest as it is with simple interest.

Guide to Comparing Auto Loan Interest Rates and Understanding Amortization Schedules

FactorDescriptionImportance in Comparing InterestRelevance to Amortization Schedules
Interest RateThe percentage of the loan charged as interest. Central to comparison; lower rates generally mean lower overall costs. Determines the portion of each payment that goes towards interest vs. principal. 
APR (Annual Percentage Rate)Includes interest rate and other loan costs. Provides a more comprehensive cost measure than just the interest rate. Reflects the true cost of the loan on an annual basis, affecting total payment. 
Loan TermDuration over which the loan is repaid. Longer terms can mean lower monthly installments but more interest over time. Influences how quickly the principal decreases and how interest accrues over time. 
Fixed vs. Variable RateFixed rates stay the same, variable rates can change. Fixed rates offer predictability; variable rates can fluctuate, affecting costs. Impacts how consistent monthly installments are and how interest is calculated over the term. 
Monthly Payment Amount paid each month. Important for budgeting; lower rates usually mean lower payments. Each payment is split into interest and principal, changing over the term. 
Total Interest Paid Total amount of interest paid over the loan term. Helps assess the total cost of the loan .Illustrated in the amortization schedule, showing interest vs. principal over time. 
Early Payment Penalties Fees for paying off the loan early. Important if you plan to pay off the loan ahead of schedule.Affects the cost-benefit analysis of making extra payments. 
Down PaymentInitial payment made when buying a car. A larger down payment can lead to lower rates. Reduces the principal amount, affecting the amortization schedule. 
Credit ScoreYour creditworthiness. Higher scores can secure lower rates.Affects the interest rate offered and thus the overall loan cost. 
Fees and Charges Additional costs like origination fees, processing fees. Adds to the cost of the loan. Should be considered in the total loan cost, affecting the amortization. 
Disclaimer: The information provided in this chart is for educational and informational purposes only and should not be construed as financial advice. The factors and descriptions are general guidelines and may vary depending on individual circumstances, lender policies, and market conditions. It is recommended to consult with a financial advisor or lending professional for personalized advice and to ensure the most current and applicable information for your specific situation. This chart does not guarantee the accuracy or applicability of any rates or terms in any particular situation.

What Is the Average Interest Rate On Car Loans?

The average interest rate for a car loan in 2021 was an APR between 4% and 6%, with a wide range below and above depending on various factors.1 The average interest rate you receive when rate shopping for a car loan can vary depending on where you live, the overall market conditions at the time, and what lender from whom you are looking into borrowing money from. 

Factors That Impact Interest Rates and Monthly Payment on Auto Loans

Here are a few other factors that will affect the interest rate you might get on an auto loan:

  • Your Credit Score: People with the highest credit scores are more likely to receive lower interest rates on vehicle loans. If you have a poor credit score, you will probably get a higher interest rate on your car loan. You might even struggle to be approved for an auto loan in the first place if your credit score is bad enough. 
  • The Down Payment: Lenders tend to charge a higher interest rate on an auto loan with little to no down payment. The risk associated with the loan increases for the lender the less money they receive in a down payment. Because of this, the lender will often increase the interest rate of the auto loan. 
  • Your Loan Term Length: The interest rates tend to be higher on vehicle loans with longer loan terms. A longer loan term will give you lower monthly payments, but it will likely mean you pay more on interest charges. Vehicles depreciate exceptionally quickly, so the longer the loan term, the more money you are paying over the actual value of the car.

How To Minimize Interest Charges On Your Car Loan Monthly Payments

If you want to save money on interest charges on your car loan, there are a couple of things you can do before obtaining a new car loan so you get a better interest rate. But there are also several things you can do to reduce the total interest you pay on an existing car loan. 

Paying Early

If you have a simple interest rate on your car loan, you could save a significant amount of money in interest charges by paying off your loan early. When you have simple interest and amortization, making unscheduled payments and regularly paying more than the minimum payment will allow you to significantly reduce the amount of interest you pay. 

Excellent Credit

If you are planning to apply for a car loan soon, you can improve your chances of getting a reasonable interest rate by boosting your credit score ahead of time. Doing a few simple things to increase your credit scores before applying for your loan can ensure you get the best car loan available with lower interest rates. 

Short Loan Terms

You might be hesitant to choose shorter loan terms because of the higher monthly payment. But by choosing shorter terms, you could access lower interest rates on your auto loan. In addition to being offered lower interest rates, you will end up paying less interest because you’ll have fewer monthly installments. 


If market conditions change part way through the life of the loan, refinancing your car loan could get you a more affordable interest rate for the remainder of your loan amount. Refinancing your auto loan could also be beneficial if your credit score has significantly improved since when you first obtained the loan. 

FAQ: Car Loan Interest Rates 

Can I negotiate the interest rate on a car loan? If so, who should I contact to negotiate the interest rate on my auto loan?

Yes, you can often negotiate the interest rate on a car loan. To do this, you should contact the loan officer at the bank, credit union, or auto dealership where you’re applying for the loan. It’s beneficial to have a good credit score and to shop around for the best rates beforehand to strengthen your negotiating position.

Where can I find tips for negotiating lower interest rates on a car loan?

Tips for negotiating lower rates on an auto loan can be found on financial advice websites, auto financing blogs, and consumer finance forums. Additionally, consulting with a financial advisor or someone experienced in auto financing can provide valuable personalized advice.

What is the difference between fixed and variable auto loan interest rates? Is it better to opt for a fixed or variable interest rate on auto loans?

Interest on fixed rate loans remains the same throughout the loan term, offering predictability in monthly payments. Interest on a variable rate loan can fluctuate based on market conditions, potentially leading to lower rates initially but with the risk of increasing later. The choice depends on your risk tolerance and financial stability; fixed rates are generally preferred for their predictability.

What happens if I miss an interest payment on auto loans?

Missing an interest payment on your auto loan can lead to late fees, increased interest rates, and negative impacts on your credit score. If missed payments continue, it could eventually lead to loan default and repossession of the vehicle.

Are there any penalties for paying off an auto loan early? What happens to the interest if I pay off my auto loan early?

Some vehicle loans include prepayment penalties for paying off the loan early. If there are no penalties, paying off early can save you money on interest. However, it’s important to read your loan agreement to understand any potential penalties and how they might affect the total cost of the loan.

What documents do I need to apply for an auto loan?

To apply for an auto loan, you typically need proof of income (like pay stubs), proof of residence (like a utility bill), a valid driver’s license, and your Social Security number. A good credit history and score are also crucial for securing lower rates.

How does the interest rate affect my monthly payment on an auto loan?

The interest rate on an auto loan directly affects the monthly payment: a higher interest rate increases the monthly payment, while a lower rate reduces it. The interest rate determines how much extra you pay on top of the principal loan amount. According to CBS News, the average auto loan payment for consumer with new cars is $717 per month, and $563 per month for consumers with used cars.2 

How do lenders determine the auto loan interest rates?

Lenders determine the interest rate for vehicle loans based on factors like the borrower’s credit score, loan term, vehicle type, and market conditions. A higher credit score often leads to lower rates, while longer loan terms and certain types of vehicles might carry higher rates.

Who offers the lowest rates on auto loans?

The lowest rates on car loans are typically offered by credit unions, online lenders, and some banks. However, the best rate for an individual depends on their credit profile and the specifics of the loan, such as the term and amount.

Who provides information on interest rates for car loans?

Information on interest rates for auto loans can be obtained from banks, credit unions, online lenders, and auto dealerships. Financial websites and comparison tools also provide updated information on current rates and comparisons between different lenders.

What is compound interest, and how does it apply to auto loans?

Compound interest is interest calculated on the initial principal and also on the accumulated interest from previous periods. However, most auto loans use simple interest, not compound interest, meaning interest is calculated only on the principal amount of the loan.

What are the pros and cons of refinancing an auto loan to get a lower interest rate?

Refinancing an auto loan to get a lower interest rate can reduce the monthly payment and the total interest paid over the life of the loan. However, it may extend the loan term and could come with additional fees. It’s important to weigh the potential savings against any additional costs or extended financial commitments.

A Word From CreditNinja on Finding the Best Auto Loan Rate

CreditNinja encourages everyone looking for any kind of loan to always research lenders and compare offers before committing. By looking through your options you may find you are able to get a better deal, lower interest rates, etc. with one lender or service provider over another. 

Looking for more information about finding loans with less interest, handling your own budget, and more? Check out the CreditNinja dojo for awesome resources like: 

  • Financial articles
  • Debt calculators 
  • Loan comparison tools 

Head over to the CreditNinja dojo to check out these free resources, available 24/7! 

1. How Does Car Loan Interest Work? | Tresl Auto Finance
2. Record share of Americans are paying $1,000 or more on monthly car payments | CBS News

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