Vehicle Price ($)
Down Payment ($)
Trade-in Value ($)
Annual Interest Rate (%)
Loan Term
Sales Tax Rate (%)
Full breakdown (click to copy)
Decision Support
Check the Comparison Term table
A shorter loan term raises the monthly payment but sharply cuts total interest — the built-in comparison across 24-84 months shows the trade-off directly, without re-entering your numbers.
Trade-in and down payment reduce interest, not just the payment
Since both reduce the loan principal directly, they lower total interest paid over the life of the loan, not just the size of each monthly payment.
Watch total interest relative to vehicle price
If total interest is a large fraction of the vehicle price, a shorter term or larger down payment would meaningfully change the real cost of ownership.
➜ Next step: Comparing this loan against other financing offers? Use the Loan EMI Comparison Calculator to see up to 4 loans side by side.
How to Use the Auto Loan Calculator
- Enter vehicle price — the total cost of the car including any dealer fees.
- Enter down payment — the upfront cash payment. Higher down payment reduces loan amount and monthly payment.
- Set loan term — typically 36, 48, 60, or 72 months. Shorter terms mean higher monthly payments but less total interest.
- Enter interest rate — your approved APR (Annual Percentage Rate). Check your credit score first — better credit scores qualify for significantly lower rates.
- Review total cost — see monthly payment, total interest paid, and total amount paid over the loan term.
🚗 Real cost of a car loan: A $30,000 car financed at 7% for 60 months costs $35,640 total — $5,640 in interest. At 12% for 72 months: $43,202 total — $13,202 in interest, nearly 44% more than the car's price. Interest rate and term dramatically impact total cost.
Understanding Auto Loans
💳 How APR Affects Cost
APR (Annual Percentage Rate) includes interest rate plus fees. At 5% APR on $25,000 for 60 months: $471/month, $3,306 total interest. At 10% APR: $531/month, $6,874 total interest. A 5% APR difference costs $3,568 more.
📊 Loan Term Trade-offs
48 months: higher payment, less total interest. 72 months: lower payment, more total interest, higher risk of going underwater (owing more than car is worth). Car values depreciate faster than long-term loans reduce — 72-month loans are financially risky.
🏦 Dealer vs Bank Financing
Dealers often mark up interest rates from the rate banks offer them (called dealer reserve). Always get pre-approved by your bank or credit union before visiting a dealer — this gives you a benchmark and negotiating power. Dealers sometimes offer 0% APR promotions that are genuinely valuable.
📉 Depreciation Reality
New cars lose 15–25% of value in the first year and 60% by year 5. A $40,000 car is worth approximately $24,000 after 3 years. If your loan balance after 3 years is $26,000, you are $2,000 underwater — you owe more than the car is worth.
🔢 GAP Insurance
Guaranteed Asset Protection covers the difference between insurance payout (car's current value) and remaining loan balance if the car is totalled. Valuable for long-term loans on new vehicles where underwater risk is high. Worth the $200–$300 cost for 60–72 month loans.
✅ Prepayment
Most auto loans allow prepayment without penalty. Making extra payments reduces principal faster, reducing interest and shortening the loan term. Even $50/month extra on a $25,000, 60-month loan at 7% saves $400 in interest and pays off 3 months early.
Getting the Best Auto Loan
Credit score impact on rates
Auto loan rates vary dramatically by credit score. Excellent credit (720+): 3–5% APR. Good credit (680–719): 5–7% APR. Fair credit (620–679): 8–12% APR. Poor credit (below 620): 15–25% APR. On a $25,000 loan for 60 months, the difference between 4% and 20% APR is over $12,000 in extra interest. Improving your credit score before financing a car is one of the highest-ROI financial moves available.
The 20/4/10 rule
Financial advisors recommend: 20% down payment minimum. Maximum 4-year (48-month) loan term. Total vehicle expenses (loan + insurance + fuel + maintenance) no more than 10% of gross monthly income. Cars that meet these criteria are genuinely affordable — those requiring exceptions are financially stretching your budget.
New vs used car financing
Used car loans typically have higher interest rates than new car loans, but the lower purchase price more than compensates. A 2-year-old car costs 20–30% less than new while retaining most of its useful life. Even at a 2% higher rate, financing a $20,000 used car instead of a $30,000 new equivalent saves $8,000–$10,000 total over the loan period.
🚗 Before signing any auto loan: Calculate the total amount paid (monthly payment × months + down payment). Subtract the car's expected value at loan payoff (use depreciation calculators). The difference is your total cost of ownership from financing — compare this to alternatives like buying a cheaper car with cash or waiting to save a larger down payment.
Auto Loan Formula
Monthly Payment = Principal × r × (1 + r)ⁿ ÷ ((1 + r)ⁿ − 1), where Principal = Vehicle Price + Sales Tax − Down Payment − Trade-in Value.
Principal
The actual amount financed, after tax is added and down payment/trade-in are subtracted from the vehicle price.
r — Monthly rate
Annual APR ÷ 12 ÷ 100, expressed as a decimal.
n — Months
The loan term in months (e.g. 60 for a 5-year loan).
Worked example
$30,000 vehicle, 8% sales tax, $5,000 down payment, no trade-in, 6% APR, 60 months: Principal = 30,000 + 2,400 − 5,000 = $27,400. Monthly rate = 6 ÷ 12 ÷ 100 = 0.005. Monthly Payment ≈ $529.72, Total Interest ≈ $4,383 over the loan term.
Assumption: a 0% APR loan is handled as a special case (principal ÷ months, no compounding) rather than causing a division-by-zero error.
Common Mistakes
Focusing only on the monthly payment
A lower monthly payment from a longer term usually means more total interest — check the Comparison table across terms, not just one number.
Forgetting sales tax
Sales tax is added to the financed amount in many jurisdictions — leaving it out of the calculation understates the real loan amount and monthly payment.
Overestimating trade-in value
Dealer trade-in offers are often below independent market value — check a valuation guide before assuming a specific trade-in figure.
Ignoring total cost of ownership
This calculator covers financing only — insurance, fuel, maintenance, and depreciation are real costs that don't appear in the loan payment itself.
Frequently Asked Questions
What is a good interest rate for a car loan?
As of 2025, average auto loan rates: new cars 5–8% APR for good credit (720+), 8–15% for fair credit. Used cars typically 1–3% higher. Credit unions often offer the best rates. Always get pre-approved before visiting a dealership.
Should I put more money down on a car?
A larger down payment reduces your monthly payment and total interest paid. It also reduces the risk of being 'upside down' (owing more than the car is worth). Aim for 10–20% down on a new car, 10%+ on used. If financing 0% APR, a down payment matters less.
What is a trade-in?
A trade-in is selling your old vehicle to the dealership as part of a new purchase. The trade-in value is deducted from the purchase price, reducing your loan amount. You can often get a better price selling privately, but a trade-in is faster and more convenient.
Is a 72 or 84 month car loan a good idea?
Longer terms mean lower monthly payments but significantly more interest. An 84-month loan on a $35,000 car at 7% costs ~$2,800 more in interest than a 60-month loan. Cars also depreciate faster than long loans pay down, leaving you owing more than the car is worth.
References
🏛️ Consumer Financial Protection Bureau
U.S. auto loan disclosure standards — consumerfinance.gov
📄 Your dealer's finance agreement
Exact rate, fees, and add-ons vary by dealer and lender — always confirm against your own official loan documents.
Last updated: 13 July 2026 · Formulas use standard reducing-balance amortization; dealer financing may include additional fees not reflected here.