Auto Loan Calculator

How to use this calculator

Six fields, all straightforward. The calculator supports three modes via the tabs at the top: standard monthly payment, a full amortization schedule, and a biweekly payment comparison.

Vehicle Price: The out-the-door selling price before taxes and fees. If you have already negotiated below MSRP, use your negotiated price. If you are still shopping, use the listed price as a starting estimate.

Down Payment: Cash you put toward the purchase upfront. More down means less borrowed, less interest, and a lower monthly payment.

Trade-In Value: Net equity from your current vehicle. If your car is worth $8,000 and you owe $5,000, enter $3,000 here. If you owe more than the car is worth (negative equity), enter 0 and add the shortfall to the vehicle price field.

Loan Term: Terms from 24 to 84 months. Most buyers choose 60 or 72 months. The 84-month option exists but almost always costs significantly more in total interest and puts you at risk of owing more than the car is worth for several years.

Interest Rate: Your lender’s quoted APR. Use the Credit Score Tier dropdown as a reference if you are estimating.

Taxes and Fees: Sales tax, title, registration, and dealer documentation fees. Common range: 7-12% of vehicle price depending on your state.

Switch to the Amortization tab to see a month-by-month breakdown of principal, interest, and remaining balance. Switch to Biweekly to see how making half-payments every two weeks instead of one monthly payment compares.

The auto loan payment formula

The standard auto loan uses a fixed-rate amortization schedule. Every payment is the same dollar amount, but the split between interest and principal changes each month.

Where:

• M = Monthly payment
• P = Principal (financed amount)
• r = Monthly interest rate (annual rate / 12)
• n = Number of payments (term in months)

This formula produces the same payment each month. In month 1, almost all of it is interest. By the final month, almost all of it is principal. The table below shows how this plays out on a $26,155 loan at 7% for 60 months:

Month	Payment	Principal	Interest	Balance
1	$517	$366	$151	$25,789
12	$517	$390	$127	$21,560
24	$517	$417	$100	$16,700
36	$517	$446	$71	$11,540
48	$517	$477	$40	$6,065
60	$517	$514	$3	$0

Notice that more than half the interest accumulates in the first half of the loan. Paying extra early matters far more than paying extra late.

Biweekly payments: how they work

Biweekly payments are a simple and underused strategy for paying off your car loan faster without dramatically changing your monthly budget.

The math: divide your monthly payment by 2 and make that payment every two weeks instead of once a month. Because there are 52 weeks in a year, you end up making 26 half-payments, which equals 13 full payments per year instead of 12. That extra payment each year goes entirely toward principal.

Not all lenders accept biweekly payment schedules natively. Check with your lender. Alternatively, divide your annual payment by 12 and add that amount to each monthly payment to achieve the same effect.

Auto loan rates by credit score tier

Credit score is the primary driver of your auto loan rate. Here is what current rates look like in 2025:

Credit Score	Tier	New Car Rate	Used Car Rate
750+	Excellent	5-7%	6-9%
720-749	Very Good	6-8%	8-10%
690-719	Good	7-9%	9-12%
630-689	Fair	10-14%	12-17%
Below 630	Poor	15-22%+	18-25%+

These rates are from a mix of banks, credit unions, and captive manufacturer finance arms. Rates for used cars are consistently higher than for new cars because used vehicles carry more collateral risk for the lender.

The cost of one credit tier: On a $25,000 loan for 60 months, the difference between a 7% rate (good credit) and a 14% rate (fair credit) is about $90 per month and $5,400 total. Improving your score by even 40-50 points before applying can drop you into a better tier.

Choosing the right loan term

The monthly payment drops as you stretch the term, but total interest goes up every time. Here is a side-by-side view for a $25,000 loan at 7%:

Term	Monthly	Total Interest	Total Repayment
24 mo	$1,119	$1,862	$26,862
36 mo	$772	$2,791	$27,791
48 mo	$598	$3,740	$28,740
60 mo	$495	$4,701	$29,701
72 mo	$428	$5,819	$30,819
84 mo	$381	$6,960	$31,960

Going from 24 to 84 months drops the payment by $738 per month but adds $5,098 in total interest. A 84-month loan at 7% means you are still paying for the car in 2032 for a vehicle purchased today.

The underwater risk with long terms: Cars depreciate fast. A new car loses 15-20% of its value in the first year and another 10% each year after that. On a 72-month loan, many buyers owe more than the car is worth for the first 3-4 years. If the car is totaled or you need to sell, you may have to pay thousands out of pocket to cover the gap. That is why gap insurance exists, but it adds to the cost.

The sweet spot for most buyers is 48-60 months on a vehicle they plan to keep 8+ years.

Down payment and trade-in strategy

Your down payment and trade-in value together determine how much you actually borrow. Every dollar of down payment reduces your financed amount dollar-for-dollar, meaning it saves you both the interest on that dollar for the full loan term.

Recommended minimum down payment: 10-20% of the vehicle price. At 15%, you are starting with meaningful equity, which keeps you from going underwater as the car depreciates.

Negative equity trade-ins: If you owe $12,000 on a car worth $9,000, you have $3,000 in negative equity. Dealers often roll this into the new loan, which means you are now financing $3,000 more than the new car is worth on day one. This is one of the most common ways buyers end up deeply underwater on car loans.

Taxes and fees: Do not forget state sales tax and fees in your total calculation. In some states, these fees are paid separately and do not get rolled into the loan. The calculator adds them to the financed amount by default, which is the most common practice for dealer-arranged financing.

Getting pre-approved and negotiating

Pre-approval is one of the simplest ways to save money on a car loan. Here is why and how:

When you walk into a dealership without financing lined up, the dealer controls both the vehicle price and the financing. Dealers earn a reserve fee from the lender when they mark up the rate you are quoted. On a $30,000 loan, even a 1% rate markup costs you about $800 over 60 months.

Steps to get pre-approved:

1. Check your credit report for errors at annualcreditreport.com and dispute any inaccuracies.
2. Apply at your bank and at least one credit union before visiting any dealership.
3. Get at least two competing offers within the same 14-30 day window so the inquiries count as one.
4. Print or screenshot your best offer and bring it to the dealer.

At the dealership: Tell the finance manager you have a pre-approval and ask them to beat it. Many dealers can access rate programs from captive lenders (like Toyota Financial or Honda Financial) at competitive rates. If they beat your pre-approval by more than 0.5%, take the dealer financing. Otherwise stick with your pre-approval.

Always negotiate the vehicle price first before discussing financing. Mixing the two makes it easy for the dealer to give with one hand and take back with the other.

How credit score affects your auto loan rate

The interest rate on your auto loan is the single biggest variable in total loan cost, and your credit score drives it more than anything else. Here’s what lenders typically offer by credit tier in 2024:

Credit score	Tier	New car APR	Used car APR
750+	Excellent	5.0-7.0%	6.5-9.0%
700-749	Good	6.5-9.0%	8.5-12.0%
650-699	Fair	9.0-13.0%	12.0-17.0%
600-649	Poor	13.0-18.0%	17.0-22.0%
Below 600	Subprime	18.0%+	22.0%+

The difference between excellent and fair credit on a $30,000 car loan at 60 months is roughly $80-120/month and $5,000-7,000 in total interest. If you’re on the border between credit tiers, delaying a purchase by 3-6 months to improve your score often saves more than any dealer negotiation.

Getting pre-approved. Apply for pre-approval from your bank or credit union before visiting a dealer. This gives you a rate benchmark, lets you shop confidently knowing your budget, and removes one dimension from dealer negotiations. Multiple loan inquiries within a 14-45 day window count as a single inquiry for FICO scoring purposes, so rate shopping doesn’t hurt your score.

60 vs 72 vs 84 month loans: the real tradeoff

Longer loan terms lower your monthly payment but significantly increase total interest paid. Here’s the math on a $35,000 auto loan at 7% APR:

Term	Monthly payment	Total interest	Total paid
36 months	$1,081	$2,916	$37,916
48 months	$836	$1,128	$37,128
60 months	$693	$6,580	$41,580
72 months	$593	$7,696	$42,696
84 months	$522	$8,848	$43,848

The 84-month loan saves $171/month vs the 60-month loan but costs $2,268 more in interest. It also keeps you “underwater” (owing more than the car is worth) for longer. Most cars lose 15-20% of value in the first year, 10-15% in year two. On an 84-month loan, you may owe more than the car is worth for the first 3-4 years, which creates risk if you need to sell or the car is totaled.