Auto Loan Calculator

Estimate your monthly car payment, total interest, and compare loan terms side by side. Includes trade-in value, sales tax, and a full year-by-year amortization schedule.

🚗 Vehicle & Loan Details

How the Auto Loan Calculator Works

This calculator uses the standard amortization formula to compute your monthly car payment. Enter the vehicle price, subtract your down payment and trade-in value, add sales tax, and the tool calculates your exact monthly payment, total interest, and full repayment schedule.

The Auto Loan Formula

Monthly payment = P × [r(1+r)n] / [(1+r)n – 1], where P is the loan principal (price − down payment − trade-in + sales tax), r is the monthly interest rate (APR ÷ 12), and n is the number of months.

How Trade-In Value Reduces Your Loan

Your trade-in value is subtracted directly from the vehicle price before calculating the loan amount. A $5,000 trade-in on a $35,000 car reduces your financed amount by $5,000, saving you hundreds or thousands in interest depending on the term length.

Choosing the Right Loan Term

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Methodology, Assumptions, and Limitations

Methodology: this calculator estimates monthly auto payments using standard amortization math and adjusts the financed balance for down payment, trade-in, taxes, and fees so buyers can compare actual borrowing cost.

Assumptions: APR, taxes, fees, and vehicle pricing are estimates. Dealer markups, GAP, warranties, lender fees, and registration costs can materially change your contract.

Limitations: this page helps with budgeting and offer comparison, but it does not replace a final buyer's order, lender disclosure, or signed financing agreement.

Worked Example

A lower monthly payment can still be the worse deal if it comes from stretching the term to 72 or 84 months. This is why total interest and overall borrowing cost matter just as much as affordability.

Primary Sources

Editorial Transparency

Last updated: March 9, 2026 · Author: CalcSharp Editorial Team · Reviewed by: CalcSharp Finance Review Desk

Frequently Asked Questions

How is a monthly auto loan payment calculated?
Monthly payments use the amortization formula: M = P × [r(1+r)^n] / [(1+r)^n – 1], where P is the loan amount (vehicle price minus down payment and trade-in plus sales tax), r is the monthly interest rate, and n is the number of months.
What is a good interest rate for a car loan?
Average rates are 5–7% for new cars and 7–10% for used cars with good credit (700+). Excellent credit (750+) can qualify for 4–5% on new vehicles. Credit unions often offer rates 1–2% lower than banks and dealerships.
Should I choose a longer loan term for lower payments?
Longer terms (72–84 months) lower monthly payments but significantly increase total interest. A 72-month loan at 6% costs about 45% more in interest than a 48-month loan. Experts recommend 48–60 months max for new cars.
How much should I put down on a car?
Experts recommend 20% down on new cars and 10% on used cars. A larger down payment reduces your monthly payment, total interest, and the risk of negative equity. Trade-in value counts toward your down payment.
How does trade-in value affect my auto loan?
Trade-in value reduces your loan amount like a down payment. A $5,000 trade-in on a $35,000 car means you finance $30,000 instead, lowering both your monthly payment and total interest paid over the life of the loan.
What does being upside down on a car loan mean?
Being upside down (negative equity) means you owe more than the car is worth. This commonly happens with low down payments and long terms. New cars depreciate 20–30% in the first year, so 0% down on a 72-month loan can leave you upside down for years.
Is it better to get a loan from a bank or dealership?
Get pre-approved from your bank or credit union first for negotiating leverage. Credit unions typically have the lowest rates. Dealerships sometimes offer manufacturer-subsidized 0% APR on new cars, but always compare at least 3 offers before committing.

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