Your Estimated Car Affordability:
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This is the estimated maximum price of a car you could afford given your inputs. Remember to factor in taxes, fees, insurance, and potential maintenance costs, which are not included in this calculation.
.calculator-container {
font-family: sans-serif;
max-width: 600px;
margin: 20px auto;
padding: 20px;
border: 1px solid #ccc;
border-radius: 8px;
box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}
.calculator-form h2, .calculator-result h3 {
text-align: center;
color: #333;
margin-bottom: 15px;
}
.calculator-form p {
color: #555;
line-height: 1.6;
margin-bottom: 20px;
}
.form-group {
margin-bottom: 15px;
display: flex;
flex-direction: column;
}
.form-group label {
display: block;
margin-bottom: 5px;
font-weight: bold;
color: #444;
}
.form-group input[type="number"] {
width: 100%;
padding: 10px;
border: 1px solid #ddd;
border-radius: 4px;
box-sizing: border-box;
}
.calculator-form button {
background-color: #4CAF50;
color: white;
padding: 12px 20px;
border: none;
border-radius: 4px;
cursor: pointer;
font-size: 16px;
width: 100%;
transition: background-color 0.3s ease;
}
.calculator-form button:hover {
background-color: #45a049;
}
.calculator-result {
margin-top: 25px;
padding: 15px;
background-color: #e8f5e9;
border: 1px solid #c8e6c9;
border-radius: 4px;
text-align: center;
}
.calculator-result p {
color: #388e3c;
font-size: 1.1em;
font-weight: bold;
}
#maxCarPrice {
font-size: 1.5em;
color: #2e7d32;
}
function calculateCarAffordability() {
var desiredMonthlyPayment = parseFloat(document.getElementById("desiredMonthlyPayment").value);
var loanTermYears = parseInt(document.getElementById("loanTerm").value);
var annualInterestRate = parseFloat(document.getElementById("annualInterestRate").value);
if (isNaN(desiredMonthlyPayment) || isNaN(loanTermYears) || isNaN(annualInterestRate) ||
desiredMonthlyPayment <= 0 || loanTermYears <= 0 || annualInterestRate < 0) {
document.getElementById("maxCarPrice").innerText = "Please enter valid positive numbers for all fields.";
return;
}
var monthlyInterestRate = annualInterestRate / 100 / 12;
var numberOfPayments = loanTermYears * 12;
// Formula to calculate maximum loan amount (which is the car price in this context)
// M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1]
// Where:
// M = Monthly Payment
// P = Principal Loan Amount (what we want to find)
// i = Monthly Interest Rate
// n = Number of Payments
// Rearranging the formula to solve for P:
// P = M [ (1 + i)^n – 1] / [ i(1 + i)^n ]
var maxLoanAmount;
if (monthlyInterestRate === 0) {
maxLoanAmount = desiredMonthlyPayment * numberOfPayments;
} else {
var numerator = Math.pow(1 + monthlyInterestRate, numberOfPayments) – 1;
var denominator = monthlyInterestRate * Math.pow(1 + monthlyInterestRate, numberOfPayments);
maxLoanAmount = desiredMonthlyPayment * (numerator / denominator);
}
// Format the result as currency
var formattedMaxLoanAmount = "$" + maxLoanAmount.toFixed(2).replace(/\d(?=(\d{3})+\.)/g, '$&,');
document.getElementById("maxCarPrice").innerText = formattedMaxLoanAmount;
}