Auto Loan Calculator — Know Your Monthly Payment Before the Dealership
This free auto loan calculator gives you a complete picture of what a car loan will actually cost. Enter the vehicle price, your down payment, trade-in value, interest rate, loan term, sales tax, and any fees — and get an instant breakdown of your monthly payment, total amount paid, total interest, and the portion of each payment that goes to principal vs interest.
The calculator also generates a full amortization schedule — either month-by-month or summarized by year — so you can see exactly how your loan balance decreases over time and plan extra payments strategically.
How Monthly Car Payment Is Calculated
The standard auto loan payment formula is based on the amortization formula used by all lenders:
Monthly Payment Formula
M = P × [r(1+r)ⁿ] / [(1+r)ⁿ − 1]
P = Principal (loan amount after down payment & trade-in)
r = Monthly interest rate (annual rate ÷ 12)
n = Total number of monthly payments (term in months)
P = Principal (loan amount after down payment & trade-in)
r = Monthly interest rate (annual rate ÷ 12)
n = Total number of monthly payments (term in months)
The loan principal P includes sales tax and fees added to the financed amount.
Example: Vehicle price $30,000 · Down payment $5,000 · Trade-in $3,000 · 4.5% APR · 60 months · 7% sales tax
Taxable amount = $30,000 × 1.07 = $32,100 · Financed = $32,100 − $5,000 − $3,000 = $24,100
Monthly rate r = 4.5% ÷ 12 = 0.375% · Result: monthly payment ≈ $447.57
Taxable amount = $30,000 × 1.07 = $32,100 · Financed = $32,100 − $5,000 − $3,000 = $24,100
Monthly rate r = 4.5% ÷ 12 = 0.375% · Result: monthly payment ≈ $447.57
How to Use the Auto Loan Calculator
- Select your currency — the calculator supports USD, EUR, GBP, JPY, CAD, AUD, and more.
- Enter the vehicle price — the full sticker or negotiated price of the car.
- Enter your down payment (optional) — cash paid upfront to reduce the loan amount.
- Enter the annual interest rate — your APR as shown on the loan offer (e.g. 4.5).
- Enter the loan term in months — common terms are 36, 48, 60, or 72 months.
- Enter trade-in value (optional) — the credit you receive for your existing vehicle.
- Enter sales tax — most US states charge 4–10% on vehicle purchases.
- Click "Calculate Payment" — results appear instantly with the full amortization table below.
Key Factors That Affect Your Auto Loan
Interest Rate (APR)
The single biggest cost driver after loan amount. A 1% difference on a $25,000 loan over 60 months can mean $700+ in extra interest. Shop multiple lenders and your own bank before accepting the dealer's rate.
Loan Term
Longer terms (72–84 months) lower monthly payments but dramatically increase total interest paid and risk leaving you "underwater" — owing more than the car is worth. Shorter terms cost less overall.
Down Payment
A larger down payment reduces both the loan principal and total interest. Putting down 20% also helps avoid being immediately underwater once the car depreciates off the lot.
Trade-In Value
Your current car's trade-in value acts like extra down payment, reducing the loan amount. Get independent trade-in quotes from CarMax or KBB before going to the dealer for accurate numbers.
Sales Tax & Fees
Sales tax typically applies to the vehicle price before discounts. Title, registration, and dealer fees of $500–$2,000 are often financed into the loan, adding to interest paid. Always ask for an itemized breakdown.
Credit Score
Your credit score determines the APR you qualify for. Scores above 720 typically get the best rates (2–4%). Scores below 600 may see rates of 10–15%+, adding thousands to total cost.
Understanding Your Amortization Schedule
An amortization schedule shows exactly how each monthly payment is split between interest and principal repayment. In the early months of your loan, a larger share of each payment goes to interest — this gradually shifts as the loan balance decreases.
For example, on a $24,000 loan at 5% for 48 months, your first payment might be $240 interest and $314 principal. By month 40, that flips: only $25 interest and $529 principal. This is why making even one extra payment early in the loan dramatically reduces total interest paid.
Money-saving tip: Making one extra payment per year — applied to principal — can reduce a 60-month loan by 4–6 months and save hundreds in interest. Use the schedule below to identify the ideal month to make extra payments.
Frequently Asked Questions
Enter the vehicle price, down payment, interest rate, loan term, sales tax, and fees, then click "Calculate Payment". The calculator uses the standard loan amortization formula: M = P × [r(1+r)ⁿ] / [(1+r)ⁿ − 1], where P is the financed amount, r is the monthly interest rate, and n is the number of payments.
In most US states, sales tax applies to the purchase price after trade-in credit but before down payment. Some states tax the full purchase price. This calculator applies sales tax to the full vehicle price — check your state's rules for exact treatment. The taxed amount is then reduced by down payment and trade-in to arrive at the financed principal.
As of 2024–2025, average new car loan rates range from 5–8% APR depending on credit score. Borrowers with excellent credit (750+) may qualify for 4–5.5%. Rates above 10% indicate lower credit scores or used-car financing, where rates are generally higher. Credit unions often offer lower rates than banks or dealerships.
A longer loan term lowers your monthly payment but significantly increases total interest. For example, a $25,000 loan at 6% over 48 months costs ~$2,970 in interest. The same loan over 72 months costs ~$4,487 — 51% more in interest — despite a lower monthly payment. Shorter terms always cost less overall.
Yes. Trade-in value is deducted from the loan principal, reducing your monthly payment and total interest. Fees (title, registration, dealer fees) are added to the financed amount, slightly increasing each payment. Both fields are optional — leave them blank if they don't apply to your situation.
An amortization schedule is a complete table of every monthly payment for the life of your loan, showing how much goes to interest, how much reduces your principal, and your remaining balance after each payment. It's useful for planning extra payments (apply to principal to reduce total interest), understanding when you'll be "above water" on the loan, and tax planning if you use the vehicle for business.
Yes. After calculating, click "Export CSV" to download the full monthly schedule as a spreadsheet file. You can also click "Print Schedule" to print or save as PDF. Both options appear in the amortization table section after calculation.
Strongly recommended. Getting pre-approved from your bank or credit union gives you a rate benchmark and negotiating leverage at the dealership. Dealers earn profit on financing — if you walk in pre-approved, you can compare their offer against yours and choose the better rate. Use this calculator to model what different rates and terms mean for your monthly payment before you go.
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