.calculator-container-wrapper-v1 {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
max-width: 800px;
margin: 0 auto;
padding: 20px;
background: #ffffff;
border: 1px solid #e0e0e0;
border-radius: 8px;
color: #333;
}
.calc-header {
text-align: center;
margin-bottom: 30px;
}
.calc-header h2 {
font-size: 28px;
color: #2c3e50;
margin-bottom: 10px;
}
.calc-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 20px;
margin-bottom: 25px;
}
@media (max-width: 600px) {
.calc-grid {
grid-template-columns: 1fr;
}
}
.input-group {
display: flex;
flex-direction: column;
}
.input-group label {
font-weight: 600;
margin-bottom: 5px;
font-size: 14px;
color: #555;
}
.input-wrapper {
position: relative;
}
.input-wrapper input {
width: 100%;
padding: 10px 10px 10px 25px;
border: 1px solid #ccc;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
}
.input-wrapper input:focus {
outline: none;
border-color: #3498db;
box-shadow: 0 0 5px rgba(52,152,219,0.3);
}
.input-symbol {
position: absolute;
left: 10px;
top: 50%;
transform: translateY(-50%);
color: #777;
}
.suffix-symbol {
left: auto;
right: 10px;
}
.calc-btn {
grid-column: 1 / -1;
background-color: #2980b9;
color: white;
border: none;
padding: 15px;
font-size: 18px;
font-weight: bold;
border-radius: 4px;
cursor: pointer;
transition: background 0.3s ease;
width: 100%;
}
.calc-btn:hover {
background-color: #2471a3;
}
.results-section {
background-color: #f8f9fa;
padding: 20px;
border-radius: 6px;
margin-top: 20px;
display: none;
border-left: 5px solid #27ae60;
}
.result-row {
display: flex;
justify-content: space-between;
margin-bottom: 10px;
padding-bottom: 10px;
border-bottom: 1px solid #eee;
}
.result-row:last-child {
border-bottom: none;
margin-bottom: 0;
padding-bottom: 0;
}
.result-label {
color: #666;
font-weight: 500;
}
.result-value {
font-weight: bold;
color: #2c3e50;
}
.highlight-result {
font-size: 24px;
color: #27ae60;
}
.content-section {
margin-top: 40px;
line-height: 1.6;
color: #444;
}
.content-section h3 {
color: #2c3e50;
border-bottom: 2px solid #eee;
padding-bottom: 10px;
margin-top: 30px;
}
.error-msg {
color: #e74c3c;
text-align: center;
margin-top: 10px;
display: none;
}
function calculateAutoLoan() {
// Get input values
var price = parseFloat(document.getElementById('vehiclePrice').value) || 0;
var down = parseFloat(document.getElementById('downPayment').value) || 0;
var trade = parseFloat(document.getElementById('tradeInValue').value) || 0;
var rate = parseFloat(document.getElementById('interestRate').value) || 0;
var months = parseFloat(document.getElementById('loanTerm').value) || 0;
var taxRate = parseFloat(document.getElementById('salesTax').value) || 0;
var fees = parseFloat(document.getElementById('fees').value) || 0;
// Element references
var resultDiv = document.getElementById('resultsSection');
var errorDiv = document.getElementById('errorDisplay');
// Validation
if (months <= 0 || price Price, base is 0.
var taxableBase = Math.max(0, price – trade);
var totalTax = taxableBase * (taxRate / 100);
// 2. Calculate Amount Financed
// Financed = Price + Tax + Fees – Down – Trade
var amountFinanced = price + totalTax + fees – down – trade;
if (amountFinanced <= 0) {
// No loan needed
resultDiv.style.display = 'block';
document.getElementById('monthlyPaymentResult').innerHTML = "$0.00";
document.getElementById('financedAmountResult').innerHTML = "$0.00";
document.getElementById('totalInterestResult').innerHTML = "$0.00";
document.getElementById('totalTaxResult').innerHTML = "$" + totalTax.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('totalCostResult').innerHTML = "$" + (price + totalTax + fees).toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2});
return;
}
// 3. Calculate Monthly Payment
var monthlyPayment = 0;
var totalInterest = 0;
var totalLoanCost = 0;
if (rate === 0) {
// Simple division if 0% interest
monthlyPayment = amountFinanced / months;
totalInterest = 0;
} else {
var monthlyRate = (rate / 100) / 12;
// Amortization Formula: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
var x = Math.pow(1 + monthlyRate, months);
monthlyPayment = (amountFinanced * x * monthlyRate) / (x – 1);
totalInterest = (monthlyPayment * months) – amountFinanced;
}
totalLoanCost = (monthlyPayment * months) + down + trade; // This is total cost including down/trade logic?
// Better definition of Total Cost for buyer = Total Loan Payments + Down + Trade + (Fees paid upfront if not financed? We assumed fees financed).
// Let's define Total Cost of Car = Price + Tax + Fees + Interest.
var totalCostOfCar = price + totalTax + fees + totalInterest;
// Display Results
resultDiv.style.display = 'block';
document.getElementById('monthlyPaymentResult').innerHTML = "$" + monthlyPayment.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('financedAmountResult').innerHTML = "$" + amountFinanced.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('totalInterestResult').innerHTML = "$" + totalInterest.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('totalTaxResult').innerHTML = "$" + totalTax.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('totalCostResult').innerHTML = "$" + totalCostOfCar.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2});
}
Auto Loan Calculator
Estimate your monthly car payments, total interest, and tax costs accurately.
$
$
$
%
%
$
Estimated Monthly Payment
$0.00
Amount Financed
$0.00
Total Interest Paid
$0.00
Total Sales Tax
$0.00
Total Cost of Car
$0.00
How Auto Loan Interest is Calculated
Understanding how your auto loan payments are derived is crucial for financial planning. An auto loan is typically an amortized loan, meaning you pay a fixed amount every month. This payment is split between paying off the principal (the car's cost) and the interest charged by the lender.
In the early stages of your loan term, a larger portion of your payment goes toward interest. As you pay down the balance, the interest charge decreases, and more of your money goes toward the principal.
Impact of Loan Term on Monthly Payments
Choosing the right loan term (length of the loan) is a balancing act.
- Short Term (e.g., 36 or 48 months): Results in higher monthly payments but significantly lower total interest costs over the life of the loan. You build equity faster.
- Long Term (e.g., 72 or 84 months): Lowers your monthly payment, making expensive cars more affordable month-to-month, but drastically increases the total interest paid and puts you at risk of being "upside-down" on the loan longer.
The Role of Down Payments and Trade-Ins
Your down payment and trade-in value reduce the "Amount Financed." A lower amount financed means you pay interest on a smaller balance. Furthermore, in many jurisdictions, trading in a vehicle can provide a tax credit, as sales tax is often calculated on the difference between the new car price and the trade-in value, rather than the full price.
What constitutes a good APR?
Annual Percentage Rate (APR) depends heavily on your credit score, the vehicle type (new vs. used), and current market rates. Generally, new cars have lower interest rates than used cars. A good credit score (720+) will typically qualify you for the lowest advertised rates, while scores below 650 may result in significantly higher interest charges.