.calc-container {
max-width: 800px;
margin: 20px auto;
font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
background: #ffffff;
border: 1px solid #e0e0e0;
border-radius: 8px;
box-shadow: 0 4px 12px rgba(0,0,0,0.05);
padding: 0;
overflow: hidden;
}
.calc-header {
background: #2c3e50;
color: #fff;
padding: 20px;
text-align: center;
}
.calc-header h2 {
margin: 0;
font-size: 24px;
}
.calc-body {
padding: 30px;
display: flex;
flex-wrap: wrap;
gap: 30px;
}
.calc-input-section {
flex: 1;
min-width: 300px;
}
.calc-results-section {
flex: 1;
min-width: 300px;
background: #f8f9fa;
padding: 20px;
border-radius: 8px;
display: flex;
flex-direction: column;
justify-content: center;
}
.form-group {
margin-bottom: 15px;
}
.form-group label {
display: block;
margin-bottom: 5px;
font-weight: 600;
color: #333;
font-size: 14px;
}
.input-wrapper {
position: relative;
display: flex;
align-items: center;
}
.currency-symbol, .percent-symbol {
position: absolute;
color: #666;
font-size: 14px;
}
.currency-symbol { left: 10px; }
.percent-symbol { right: 10px; }
.form-control {
width: 100%;
padding: 10px 10px 10px 25px; /* Space for $ */
border: 1px solid #ddd;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
}
.input-with-percent .form-control {
padding-right: 25px; /* Space for % */
}
select.form-control {
padding: 10px;
}
.calc-btn {
width: 100%;
background: #3498db;
color: white;
border: none;
padding: 15px;
font-size: 16px;
font-weight: bold;
border-radius: 4px;
cursor: pointer;
transition: background 0.3s;
margin-top: 10px;
}
.calc-btn:hover {
background: #2980b9;
}
.result-card {
text-align: center;
margin-bottom: 20px;
padding-bottom: 20px;
border-bottom: 1px solid #ddd;
}
.result-card:last-child {
border-bottom: none;
margin-bottom: 0;
padding-bottom: 0;
}
.result-label {
font-size: 14px;
color: #666;
margin-bottom: 5px;
}
.result-value {
font-size: 32px;
font-weight: 800;
color: #2c3e50;
}
.result-sub-value {
font-size: 20px;
font-weight: 600;
color: #555;
}
.article-content {
max-width: 800px;
margin: 40px auto;
font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
line-height: 1.6;
color: #333;
}
.article-content h2 {
color: #2c3e50;
margin-top: 30px;
}
.article-content ul {
margin-bottom: 20px;
}
.article-content li {
margin-bottom: 10px;
}
.highlight-box {
background: #e8f4fd;
border-left: 4px solid #3498db;
padding: 15px;
margin: 20px 0;
}
@media (max-width: 600px) {
.calc-body {
flex-direction: column;
}
}
Estimated Monthly Payment
$0.00
Total Interest Paid
$0.00
Total Cost of Car (Loan + Interest)
$0.00
function calculateCarLoan() {
// 1. Get DOM elements
var vehiclePriceInput = document.getElementById("vehiclePrice");
var tradeInInput = document.getElementById("tradeIn");
var downPaymentInput = document.getElementById("downPayment");
var salesTaxInput = document.getElementById("salesTax");
var interestRateInput = document.getElementById("interestRate");
var loanTermInput = document.getElementById("loanTerm");
// 2. Parse values or default to 0
var price = parseFloat(vehiclePriceInput.value) || 0;
var tradeIn = parseFloat(tradeInInput.value) || 0;
var downPayment = parseFloat(downPaymentInput.value) || 0;
var taxRate = parseFloat(salesTaxInput.value) || 0;
var apr = parseFloat(interestRateInput.value) || 0;
var months = parseInt(loanTermInput.value) || 60;
// 3. Calculation Logic
// Logic: Tax usually applies to (Price – TradeIn) in many states.
// We will assume Trade-In reduces taxable amount for this general calculator.
var taxableAmount = price – tradeIn;
if (taxableAmount < 0) taxableAmount = 0;
var taxAmount = taxableAmount * (taxRate / 100);
var totalPrice = taxableAmount + taxAmount; // Price with tax, minus trade-in
// Amount to Finance = Total Price (after trade/tax) – Cash Down Payment
// Note: If trade-in covers everything, loan is 0.
var loanAmount = totalPrice – downPayment;
var monthlyPayment = 0;
var totalInterest = 0;
var totalCost = 0;
if (loanAmount <= 0) {
loanAmount = 0;
monthlyPayment = 0;
totalInterest = 0;
totalCost = downPayment + tradeIn + taxAmount; // Just what they paid upfront
} else {
if (apr === 0) {
// Simple division if 0% financing
monthlyPayment = loanAmount / months;
totalInterest = 0;
} else {
// Standard Amortization Formula: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
var monthlyRate = (apr / 100) / 12;
var x = Math.pow(1 + monthlyRate, months);
monthlyPayment = (loanAmount * x * monthlyRate) / (x – 1);
totalInterest = (monthlyPayment * months) – loanAmount;
}
totalCost = (monthlyPayment * months) + downPayment + tradeIn;
}
// 4. Update UI
document.getElementById("monthlyPaymentResult").innerText = "$" + monthlyPayment.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("totalInterestResult").innerText = "$" + totalInterest.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("totalCostResult").innerText = "$" + totalCost.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("financedAmountResult").innerText = "$" + loanAmount.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2});
}
// Run once on load to populate example data
calculateCarLoan();
Understanding Your Auto Loan Calculation
Buying a car is one of the largest financial decisions most people make. Using a specialized Auto Loan Calculator helps you understand the true cost of vehicle ownership beyond just the sticker price. This tool breaks down how your trade-in value, down payment, and especially your interest rate (APR) affect your monthly budget.
How the Formula Works
This calculator uses the standard amortization formula used by most banks and dealerships. It takes into account:
- Principal: The final loan amount after subtracting your trade-in and down payment from the vehicle price (plus taxes).
- Interest Rate (APR): The annual percentage rate charged by the lender. A lower credit score typically results in a higher APR.
- Loan Term: The length of time you have to pay back the loan. Common terms are 60 months (5 years) or 72 months (6 years).
SEO Tip: Extending your loan term from 60 to 84 months will lower your monthly payment, but significantly increase the Total Interest Paid over the life of the loan. Use the calculator above to compare 60-month vs 72-month terms.
The Impact of Sales Tax and Trade-Ins
In many regions, trading in your old vehicle offers a tax advantage. The sales tax is often calculated on the difference between the new car's price and your trade-in value, rather than the full price of the new car. Our calculator applies the tax rate to the Price - Trade-In value to give you a more accurate estimate of your "out-the-door" cost.
How to Lower Your Monthly Car Payment
- Increase your Down Payment: Paying more upfront reduces the principal, which lowers both the monthly payment and total interest.
- Improve your Credit Score: A lower APR can save you thousands. For example, on a $30,000 loan, the difference between 5% and 10% interest is roughly $70 per month.
- Choose a Cheaper Vehicle: Stick to a car price that fits your budget, aiming for the "20/4/10 rule" (20% down, 4-year term, payment less than 10% of monthly income).