Auto Loan Calculator
Estimate your monthly car payment with down payment, trade-in, interest rate, and sales tax
Loan Details
Payment Summary
Monthly Payment
$586.98
Loan Amount
$30.00K
Total Interest
$5.22K
Total Cost of Loan
$35.22K
Sales Tax Amount
$0.00
Cost Breakdown
Complete Guide to Auto Loan Calculations
What Is an Auto Loan?
An auto loan is a secured installment loan used to purchase a vehicle. The car itself serves as collateral, which typically results in lower interest rates compared to unsecured personal loans. Loan terms generally range from 24 to 84 months, with most buyers choosing 60-month financing.
Your total cost depends on four main factors: the amount financed, interest rate, loan term, and any applicable fees or taxes. Use our Loan Amortization Calculator to see a month-by-month breakdown of how each payment splits between principal and interest.
Auto Loan Payment Formula
Monthly Payment (PMT):
PMT = P × r / (1 − (1 + r)^(−n))
Where: P = loan principal (price + tax − down payment − trade-in), r = monthly interest rate (annual rate ÷ 12 ÷ 100), n = total number of monthly payments
Benefits of Calculating Before You Buy
Budget Confidence
Know exactly what you can afford before stepping into a dealership, preventing pressure-driven overspending.
Term Comparison
Compare 36, 48, 60, and 72-month terms side by side to find the sweet spot between affordable payments and total cost.
Negotiation Power
Understand the true cost of dealer financing offers versus pre-approved bank or credit union rates.
Down Payment Planning
See how increasing your down payment or trade-in value directly reduces monthly payments and total interest. Pair with our Savings Goal Calculator to plan your down payment timeline.
Tips for Getting the Best Auto Loan
Get pre-approved: Secure financing from your bank or credit union before visiting the dealer. This gives you a baseline rate to compare against dealer offers.
Put 20% down: A larger down payment reduces your loan-to-value ratio, often qualifying you for better rates and avoiding negative equity. Check our EMI Loan Calculator for quick EMI estimates at different down payment levels.
Keep terms under 60 months: While 72–84 month loans have lower monthly payments, you pay thousands more in interest and risk being "underwater" (owing more than the car is worth) for years.
Common Auto Loan Mistakes
Focusing Only on Monthly Payment
Dealers often stretch the term to lower monthly payments, hiding thousands in extra interest. Always compare the total cost of the loan, not just the monthly figure.
Ignoring Total Interest on Long Terms
A $30,000 loan at 6.5% costs $4,296 in interest over 48 months but $6,580 over 72 months — that is $2,284 extra for the convenience of lower payments. Use the Break-Even Calculator to see when paying more monthly breaks even on total cost.
Skipping the Trade-In Research
Not knowing your current car's market value leaves money on the table. Research your trade-in value independently before negotiating — the dealer's first offer is typically 10–20% below market.
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OpenFrequently Asked Questions
How is an auto loan monthly payment calculated?
The monthly payment uses the standard amortization formula: PMT = P × r / (1 − (1+r)^−n), where P is the amount financed (vehicle price + tax − down payment − trade-in), r is the monthly interest rate (annual rate ÷ 12), and n is the number of monthly payments. For example, financing $30,000 at 6.5% for 60 months gives a monthly payment of $586.87.
What factors affect my auto loan interest rate?
Key factors include your credit score (higher scores get lower rates), loan term (shorter terms typically have lower rates), new vs. used vehicle (used cars often carry higher rates), down payment size (larger down payments reduce lender risk), and current market conditions set by central banks.
Is a longer or shorter loan term better?
A shorter term (36–48 months) means higher monthly payments but significantly less total interest. A 72-month term on $30,000 at 6.5% costs $3,300 more in interest than a 48-month term. Choose the shortest term your budget allows to minimize total cost.
How does a trade-in reduce my loan amount?
Your trade-in value is subtracted from the vehicle price before financing, reducing the principal you borrow. If you buy a $35,000 car with a $8,000 trade-in and $5,000 down, you finance only $22,000 (plus any applicable tax), resulting in lower monthly payments and less total interest.
Should I include sales tax in my auto loan?
Sales tax is typically added to the vehicle price before financing in most jurisdictions (ranging from 0% to over 10%). Including it in your loan increases the principal and total interest paid. If possible, paying sales tax upfront with your down payment saves money over the loan term.
How does this compare to the Loan Amortization Calculator?
The Auto Loan Calculator is tailored for vehicle purchases with fields for trade-in value and sales tax — factors specific to car buying. The Loan Amortization Calculator provides a generic month-by-month principal/interest schedule for any fixed-rate loan. Use both together: this tool for quick payment estimates, the amortization tool for a detailed repayment schedule.