The car loan calculator instantly computes your monthly payment based on vehicle price, down payment, trade-in value, interest rate and loan term. Use it before visiting a dealership to know exactly what you can afford — and to avoid being sold a longer loan term that costs thousands more in interest.
Enter the car price, your down payment (cash), any trade-in value, the loan interest rate (APR), and the loan term in months. The calculator uses the standard amortization formula to produce your exact monthly payment and total interest cost.
New car APRs (2024) range from 5–10% depending on credit score. Used car rates are typically 1–3% higher. Credit unions often offer rates 1–2% lower than dealership financing.
Reach for this tool whenever a financial decision hinges on this type of calculation. Small differences in rate or term become large differences in total cost or return over multi-year horizons — differences that only become visible when you run the actual numbers.
A frequent error is using annual rates where monthly rates are required (or vice versa). Simply dividing an annual rate by 12 is only an approximation — the correct conversion for compound calculations uses the (1 + r)^(1/12) − 1 formula.
A first-time buyer models three scenarios before making an offer: 10%, 15%, and 20% deposit on a £280,000 property. The calculator shows exactly how the monthly payment and total interest cost change with each deposit level, making the decision visible rather than speculative.
Monthly Car Payment Formula
M = P × [r(1+r)^n] / [(1+r)^n − 1]
P = loan amount (price − down payment − trade-in), r = monthly rate (APR ÷ 12), n = term in months.
You buy a $32,000 car with $4,000 down and 0% trade-in at 6.9% APR for 60 months.
Result: Monthly payment ≈ $551 — Total interest = $5,060
For excellent credit (720+): 4–6%. Good credit (680–719): 6–9%. Fair credit (620–679): 9–15%. Rates vary by lender and new vs used.
36–48 months is ideal. 72-month loans lower payments but dramatically increase total interest. Avoid loans longer than the depreciation curve of the car.
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