Auto Loan Calculator with Trade-In

Worked example

Example: $35,000 new car, $3,000 down, $8,000 trade-in, 6.9% APR, 60 months—about $24,000 financed after trade-in, near $475/month before tax.

When to use this

• Deciding between trading in and selling privately.
• Comparing dealer offers that include trade allowance.
• Budgeting a replacement vehicle with equity from your current car.

Common examples

• $25,000 vehicle with $3,000 down, 6.9% APR, 60 months → about $435/month on $22,000 financed (before tax, title, and dealer fees).
• $35,000 SUV with $5,000 down, 7.2% APR, 72 months → about $514/month on $30,000 financed—lower payment than 60 months but roughly $1,400 more total interest.
• $45,000 truck with $8,000 down plus a $6,000 trade-in, 5.9% APR, 48 months → about $727/month on $31,000 financed for a shorter payoff window.
• $42,000 SUV with $7,000 down, 5.4% APR, 48 months → about $815/month before tax on roughly $35,000 financed.
• Used $18,500 sedan with $2,000 down, 8.9% APR, 36 months → higher payment but less total interest than 72 months at the same rate.

Common mistakes

• Using the dealer's first trade quote without independent appraisal.
• Ignoring negative equity rolled into the new loan.
• Forgetting tax treatment differs by state.

How it works

Enter the vehicle price, down payment ($ or % of vehicle price), interest rate, and loan term in months. Optional trade-in, sales tax, doc fees, and negative equity roll-in adjust the amount financed. The calculator uses the standard amortizing loan formula for monthly payment, total interest, and total cost.

Limitations

Estimates assume a fixed APR and equal monthly payments. Dealer fees, gap insurance, and regional tax rules are not included. Confirm final terms with your lender.

Privacy and file handling

Your data stays on your device and is not uploaded.

Accuracy & methodology

This section documents how the calculator works, what it leaves out, and when results were last reviewed. Figures are educational estimates—not professional advice—and are not labeled "current" unless tied to automatically updated reference data.

Formula source or methodology

Standard amortizing auto loan: monthly payment from principal, annual rate, and term; schedules total interest and payoff.

Jurisdiction

General (lender rules vary by country and state)

Unit system

Currency; annual rate %; term in months or years per form

Rounding method

Currency amounts round to two decimal places (half up via Math.round × 100 / 100).

Assumptions

• Fixed rate for the full loan term
• No balloon payment or residual value buyout

Known omissions

• Not tax, legal, investment, or lending advice. Confirm material decisions with qualified professionals.
• Dealer documentation fees, gap insurance, and extended warranties unless entered separately
• Registration, title, and license fees unless you add them outside this calculator
• Prepayment penalties, variable rates, and lease or balloon residuals
• Sales tax is estimated from your percent input—verify local rules with your dealer or DMV

Test cases (automated)

• Valid principal, rate, and term yield a positive monthly payment
• Zero or negative principal is rejected

Version & last verified

Logic version 1.0. Content and formulas last verified 2026-07-24.

Important notice

Results are estimates for educational purposes and are not financial advice. Taxes, fees, insurance, and lender-specific terms may not be included. Consult a qualified financial professional for personal guidance.