Car Loan Calculator

What is Car Loan Calculator?

A car loan calculator helps you understand the true cost of financing a vehicle by computing the monthly payment, total interest, and overall cost of an auto loan. It uses the standard amortization formula for fixed-rate installment loans: Monthly Payment = P × [r(1+r)^n] / [(1+r)^n − 1], where P is the loan principal, r is the monthly interest rate (APR ÷ 12), and n is the total number of monthly payments.\n\nThe calculator accounts for the car price, down payment, trade-in value, sales tax, and interest rate. Sales tax is applied to the purchase price minus the trade-in value in most states. The loan amount equals the car price plus tax, minus the down payment and trade-in. This gives you an accurate picture of your financing obligation before you visit a dealership.\n\nUnderstanding the total cost — not just the monthly payment — is critical. A longer loan term (6–7 years) reduces monthly payments but significantly increases total interest paid and risks negative equity, where you owe more than the car is worth. A shorter term (2–4 years) costs less overall but requires higher monthly payments. This calculator shows both perspectives so you can make an informed decision.

How to Use

1. Enter the car's purchase price (MSRP or negotiated price).
2. Add your down payment amount — ideally 20% to avoid negative equity.
3. Include trade-in value if you have a vehicle to trade.
4. Select the loan term (2–7 years typical for auto loans; shorter terms save on interest).
5. Enter the interest rate (APR) offered by your lender — check bank, credit union, and dealership rates.
6. Add your state's sales tax rate (typically 4–10%; some states deduct trade-in value from taxable amount).
7. Click Calculate to see your complete payment breakdown, total interest, and amortization schedule.

Tips & Best Practices

• Shorter loan terms (2–3 years) save significantly on interest — a $30,000 loan at 7.5% costs $3,604 in interest over 3 years vs $7,747 over 6 years
• 20% down payment reduces monthly costs and total interest, and helps avoid negative equity
• New car loans typically have lower rates than used car loans — but new cars depreciate 20%+ in the first year
• Consider total cost, not just monthly payment, when choosing a loan term — dealers often push longer terms to lower the payment
• Trade-in value can significantly reduce your loan amount and may reduce sales tax in most states
• Shop rates from banks, credit unions, and dealerships — credit unions often offer the best rates for average credit scores

Frequently Asked Questions

Real-world Examples

Car price:           $30,000
Down payment:        $5,000 (16.7%)
Sales tax (8%):      $30,000 × 8% = $2,400
Loan amount:         $30,000 + $2,400 − $5,000 = $27,400
Interest rate:       7.5% APR
Loan term:           5 years (60 months)

Monthly rate:        7.5% / 12 = 0.625%
Monthly payment:     $27,400 × [0.00625(1.00625)^60] / [(1.00625)^60 − 1]

Monthly payment:     $549
Total payments:      $549 × 60 = $32,940
Total interest:      $32,940 − $27,400 = $5,540
Total cost:          $30,000 + $2,400 + $5,540 = $37,940

Interest vs principal: 16.8% of payments go to interest

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