Estimate your monthly car payment by adjusting the loan details and seeing how your credit score might affect the interest rate.
3 Years
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6 Years
7 Years
700
Rate adjusts based on credit score.
Your Estimated Monthly Payment:
$0.00
Understanding Your Car Payment and Credit Score
Calculating your monthly car payment is a crucial step in the car buying process. While the sticker price of the vehicle is important, the interest rate on your auto loan can significantly impact the total amount you pay over time and your monthly budget. Your credit score is a primary factor lenders use to determine this interest rate.
How Your Credit Score Affects Your Car Loan Interest Rate
Lenders assess your creditworthiness based on your credit score. A higher credit score generally indicates a lower risk to the lender, which translates to a lower interest rate on your loan. Conversely, a lower credit score suggests a higher risk, often resulting in a higher interest rate.
The estimated interest rates below are a general guideline. Actual rates can vary based on the lender, current market conditions, loan term, and your specific financial profile.
Excellent Credit (780-850): Typically qualify for the lowest rates, often below 4%.
Very Good Credit (720-779): Rates may be slightly higher, around 4% – 6%.
Good Credit (670-719): Expect rates in the 6% – 9% range.
Fair Credit (600-669): Rates can be significantly higher, 10% – 15% or more.
Poor Credit (Below 600): May face very high rates, often above 15%, or may struggle to get approved without a co-signer or a larger down payment.
The Math Behind Your Car Payment
The monthly car payment is calculated using the following loan amortization formula:
M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1]
Where:
M = Your total monthly payment.
P = The principal loan amount (Car Price – Down Payment).
i = Your monthly interest rate (Annual Interest Rate / 12 / 100).
n = The total number of payments (Loan Term in Years * 12).
Using This Calculator
This calculator helps you visualize how different factors influence your monthly payment:
Car Price: The total cost of the vehicle.
Down Payment: The amount paid upfront, reducing the loan principal.
Loan Term: The duration of the loan. Longer terms mean lower monthly payments but more interest paid overall.
Credit Score: This calculator uses your estimated credit score to suggest a relevant interest rate. Adjust the slider to see how changes in your creditworthiness could affect your loan's APR and your monthly payment.
By inputting your details and adjusting the credit score slider, you can get a clearer picture of potential car loan costs and understand the importance of maintaining a good credit standing.
function getInterestRate(creditScore) {
var rate = 5.0; // Default rate for good credit
if (creditScore >= 780) {
rate = 3.5; // Excellent credit
} else if (creditScore >= 720) {
rate = 5.0; // Very Good credit
} else if (creditScore >= 670) {
rate = 7.5; // Good credit
} else if (creditScore >= 600) {
rate = 12.0; // Fair credit
} else {
rate = 18.0; // Poor credit
}
return rate;
}
function updateCreditScoreDisplay() {
var creditScoreInput = document.getElementById("creditScore");
var creditScoreDisplay = document.getElementById("creditScoreDisplay");
var interestRateInput = document.getElementById("interestRate");
var rateInfoDisplay = document.getElementById("rateInfo");
var currentCreditScore = parseInt(creditScoreInput.value, 10);
var estimatedRate = getInterestRate(currentCreditScore);
creditScoreDisplay.textContent = currentCreditScore;
interestRateInput.value = estimatedRate.toFixed(1);
var rateInfoText = "";
if (currentCreditScore >= 780) {
rateInfoText = "Excellent Credit: You likely qualify for the best rates.";
} else if (currentCreditScore >= 720) {
rateInfoText = "Very Good Credit: Expect competitive rates.";
} else if (currentCreditScore >= 670) {
rateInfoText = "Good Credit: Rates will be moderate.";
} else if (currentCreditScore >= 600) {
rateInfoText = "Fair Credit: Rates may be higher.";
} else {
rateInfoText = "Poor Credit: Rates could be significantly higher, or approval may be challenging.";
}
rateInfoDisplay.textContent = rateInfoText;
}
function calculateCarPayment() {
var carPrice = parseFloat(document.getElementById("carPrice").value);
var downPayment = parseFloat(document.getElementById("downPayment").value);
var loanTermYears = parseInt(document.getElementById("loanTerm").value, 10);
var interestRatePercent = parseFloat(document.getElementById("interestRate").value);
var monthlyPaymentElement = document.getElementById("monthlyPayment");
// Input validation
if (isNaN(carPrice) || carPrice <= 0) {
alert("Please enter a valid Car Price.");
return;
}
if (isNaN(downPayment) || downPayment carPrice) {
alert("Down payment cannot be greater than the car price.");
return;
}
if (isNaN(loanTermYears) || loanTermYears <= 0) {
alert("Please select a valid Loan Term.");
return;
}
if (isNaN(interestRatePercent) || interestRatePercent < 0) {
alert("Please enter a valid Interest Rate.");
return;
}
var loanAmount = carPrice – downPayment;
var monthlyInterestRate = (interestRatePercent / 100) / 12;
var numberOfPayments = loanTermYears * 12;
var monthlyPayment = 0;
if (monthlyInterestRate === 0) {
monthlyPayment = loanAmount / numberOfPayments;
} else {
monthlyPayment = loanAmount * (monthlyInterestRate * Math.pow(1 + monthlyInterestRate, numberOfPayments)) / (Math.pow(1 + monthlyInterestRate, numberOfPayments) – 1);
}
// Check for NaN result
if (isNaN(monthlyPayment) || !isFinite(monthlyPayment)) {
monthlyPaymentElement.textContent = "$0.00";
alert("Calculation error. Please check your inputs.");
} else {
monthlyPaymentElement.textContent = "$" + monthlyPayment.toFixed(2);
}
}
// Initialize display on page load
window.onload = function() {
updateCreditScoreDisplay();
calculateCarPayment(); // Calculate initial payment based on default values
};