Plan your car financing with a clearer payment view

A loan quote can look simple until you compare monthly payment, total interest, and the real financed amount side by side. This auto loan calculator helps you connect price, tax, trade-in value, and APR to the full repayment picture.

Monthly payment and total interest Loan amount with tax and trade-in Amortization schedule by month Charts, compare, share
Monthly payment
Estimate your payment before applying
Total interest
See financing cost over the full term
Guide
APR, term, tax, and trade-in basics

How to use the Auto Loan Calculator

  1. 1

    Enter price and upfront amounts

    Type the vehicle price, down payment, and trade-in value. Trade-in is optional and can stay at zero.

  2. 2

    Set tax and financing terms

    Enter sales tax rate, APR, and the loan term in months. The calculator uses monthly amortization math.

  3. 3

    Calculate and review the result

    See monthly payment, total interest, total amount paid, and a breakdown of principal vs interest.

  4. 4

    Check the schedule and compare scenarios

    Review the amortization table, then store scenarios to compare different APRs, terms, or down payments.

Detailed guide and references▶

Why this calculator helps

Auto loan offers are often compared by monthly payment only. That is useful, but it does not tell the full story. A lower payment can come from a longer term, which often increases total interest.

This calculator shows the payment and the total cost together so you can compare trade-offs more clearly. It also separates loan amount, sales tax, and interest to make the financing math easier to understand.

Toy car and cash representing auto financing
Looking at payment, total interest, and loan amount together makes it easier to compare financing options.

Inputs and assumptions

The calculator uses a simple set of inputs commonly seen on car financing worksheets.

  • Vehicle price the purchase price before loan financing.
  • Down payment cash paid upfront to reduce the amount financed.
  • Trade-in value value credited from your current vehicle.
  • Sales tax rate local tax rate used to estimate tax added to the deal.
  • APR annual percentage rate for the loan.
  • Loan term number of monthly payments.

This page assumes sales tax is applied to vehicle price minus trade-in value. That is common in some places, but not universal. Dealer fees, registration, insurance, and lender fees are not included.

Formulas and workflow

Step 1. Estimate taxable amount and sales tax

Taxable amount = max(vehicle price − trade-in value, 0) Sales tax = taxable amount × tax rate

Step 2. Estimate amount financed

Loan amount = vehicle price + sales tax − down payment − trade-in value

Step 3. Monthly payment using amortization

For standard fixed-rate auto loans, each monthly payment includes both principal and interest. The calculator uses the common amortization formula.

Monthly rate r = APR ÷ 12 Monthly payment P = [r × PV] ÷ [1 − (1 + r)^−n] PV = loan amount n = total number of monthly payments

If APR is 0%, the calculator simply divides the loan amount by the number of months.

Step 4. Total paid and total interest

Total amount paid to lender = monthly payment × n Total interest = total amount paid to lender − loan amount

What affects total auto loan cost

APR

  • Higher APR increases interest each month and usually raises total cost.
  • Small APR differences can matter a lot on longer loan terms.

Loan term

  • Longer terms usually reduce monthly payment.
  • Longer terms also often increase total interest paid.

Down payment and trade-in value

  • Higher upfront credit reduces the financed amount.
  • A lower financed amount usually reduces both payment and total interest.

Sales tax and local rules

  • Tax handling varies by country and region.
  • Some places tax trade-ins differently, so lender paperwork may differ from the estimate.

Worked examples

Use scenario comparison to test how financing choices change the result.

  • Scenario A lower down payment and shorter term might raise the monthly payment but reduce long-run interest.
  • Scenario B longer term might lower the monthly payment but increase total interest cost.
  • Scenario C adding trade-in value can reduce the loan amount and improve both monthly payment and total cost.

The compare table is helpful when you are deciding between dealer offers or thinking about a larger down payment.

Practical tips

  • Use your lender quote or pre-approval APR instead of a rough guess when possible.
  • Confirm if tax, title, registration, or dealer fees are financed.
  • Compare monthly payment and total interest together, not separately.
  • Test more than one term length to see the payment and cost trade-off.
  • Use the amortization schedule to understand how slowly principal falls in the early months at higher APRs.

FAQs

Does this include dealer fees and registration?▶

No. This calculator focuses on the core loan estimate. Dealer fees, registration, insurance, and lender specific charges are not included unless you manually add them into the vehicle price.

Can I calculate a 0% APR loan?▶

Yes. When APR is 0%, the monthly payment is calculated as loan amount divided by the number of months, and total interest becomes zero.

Why is my lender quote different?▶

Lenders may round differently, include additional fees, or use different tax treatment rules. Use this tool as a planning estimate and confirm the exact contract terms with your lender.

Can I use this outside the U.S.?▶

Yes, as long as you keep all inputs in the same currency. Just make sure your local sales tax rules and financing terms match the assumptions used here.

Key takeaways

  • Monthly payment is only one part of the decision. Total interest matters too.
  • Longer terms usually lower payments but can raise overall financing cost.
  • Down payment and trade-in value can reduce the financed amount and interest.
  • Tax handling can change the result, so confirm local rules and lender assumptions.
  • Compare multiple scenarios before accepting a final offer.

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Calculator

Enter vehicle price, down payment, trade-in value, sales tax, APR, and loan term, then press Calculate.
Assumption: sales tax is calculated on vehicle price minus trade-in value. Local rules may differ.

The results shown are estimates for planning and education. Actual lender offers may include different taxes, fees, and rounding rules.