Auto Loan Calculator
Your Estimated Monthly Payment:
—
Understanding Your Auto Loan
An auto loan calculator is a valuable tool for anyone looking to finance a vehicle. It helps you estimate your monthly payments, the total interest you'll pay over the life of the loan, and the overall cost of the vehicle. By understanding these figures, you can make a more informed decision and budget effectively for your car purchase.
How it Works:
The calculator uses a standard formula for calculating amortizing loan payments. Here's a breakdown of the key components:
- Loan Amount: This is the principal amount you are borrowing to purchase the car. It typically includes the price of the vehicle minus any down payment you make.
- Annual Interest Rate: This is the percentage charged by the lender for borrowing the money. A lower interest rate means you'll pay less in interest over time.
- Loan Term: This is the total duration of the loan, usually expressed in years. A shorter loan term generally results in higher monthly payments but less total interest paid. A longer term means lower monthly payments but more interest paid overall.
The Calculation:
The monthly payment (M) is calculated using the following formula:
M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1]
Where:
- P = Principal loan amount
- i = Monthly interest rate (Annual interest rate / 12)
- n = Total number of payments (Loan term in years * 12)
The calculator also determines:
- Total Interest Paid: Calculated as (Monthly Payment * Total Number of Payments) – Principal Loan Amount.
- Total Cost of the Loan: Calculated as Principal Loan Amount + Total Interest Paid.
Example:
Let's say you're looking to buy a car and need a loan of $25,000 with an annual interest rate of 5.5% for a term of 5 years. Plugging these figures into our calculator:
- Loan Amount (P): $25,000
- Annual Interest Rate: 5.5%
- Monthly Interest Rate (i): 5.5% / 12 months = 0.00458333
- Loan Term: 5 years
- Total Number of Payments (n): 5 years * 12 months/year = 60 months
Using the formula, the estimated monthly payment would be approximately $476.62. Over the 5-year term, you would pay approximately $3,597.20 in interest, making the total cost of the loan around $28,597.20.
Use this calculator to explore different loan scenarios and find the best option for your budget!
function calculateAutoLoan() {
var loanAmount = parseFloat(document.getElementById("loanAmount").value);
var interestRate = parseFloat(document.getElementById("interestRate").value);
var loanTerm = parseFloat(document.getElementById("loanTerm").value);
var monthlyPaymentResultElement = document.getElementById("monthlyPaymentResult");
var totalInterestResultElement = document.getElementById("totalInterestResult");
var totalCostResultElement = document.getElementById("totalCostResult");
// Clear previous results
monthlyPaymentResultElement.innerHTML = "–";
totalInterestResultElement.innerHTML = "";
totalCostResultElement.innerHTML = "";
// Input validation
if (isNaN(loanAmount) || isNaN(interestRate) || isNaN(loanTerm) || loanAmount <= 0 || interestRate < 0 || loanTerm <= 0) {
monthlyPaymentResultElement.innerHTML = "Please enter valid numbers for all fields.";
return;
}
var monthlyInterestRate = (interestRate / 100) / 12;
var numberOfPayments = loanTerm * 12;
// Calculate monthly payment using the loan payment formula
// M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1]
var monthlyPayment = loanAmount * (monthlyInterestRate * Math.pow(1 + monthlyInterestRate, numberOfPayments)) / (Math.pow(1 + monthlyInterestRate, numberOfPayments) – 1);
// Handle potential division by zero or very small numbers that might cause issues
if (isNaN(monthlyPayment) || !isFinite(monthlyPayment)) {
monthlyPaymentResultElement.innerHTML = "Calculation resulted in an error. Please check your inputs.";
return;
}
var totalInterestPaid = (monthlyPayment * numberOfPayments) – loanAmount;
var totalCost = loanAmount + totalInterestPaid;
monthlyPaymentResultElement.innerHTML = "$" + monthlyPayment.toFixed(2);
totalInterestResultElement.innerHTML = "
Total Interest Paid: $" + totalInterestPaid.toFixed(2);
totalCostResultElement.innerHTML = "
Total Cost of Loan: $" + totalCost.toFixed(2);
}
#auto-loan-calculator-wrapper {
font-family: sans-serif;
max-width: 700px;
margin: 20px auto;
padding: 20px;
border: 1px solid #ddd;
border-radius: 8px;
box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}
#auto-loan-calculator-inputs .form-group {
margin-bottom: 15px;
}
#auto-loan-calculator-inputs label {
display: block;
margin-bottom: 5px;
font-weight: bold;
}
#auto-loan-calculator-inputs input[type="number"] {
width: calc(100% – 12px);
padding: 8px;
border: 1px solid #ccc;
border-radius: 4px;
box-sizing: border-box;
}
#auto-loan-calculator-inputs button {
background-color: #007bff;
color: white;
padding: 10px 15px;
border: none;
border-radius: 4px;
cursor: pointer;
font-size: 16px;
margin-top: 10px;
}
#auto-loan-calculator-inputs button:hover {
background-color: #0056b3;
}
#auto-loan-calculator-results {
margin-top: 30px;
padding-top: 20px;
border-top: 1px solid #eee;
}
#auto-loan-calculator-results h3 {
margin-bottom: 15px;
color: #333;
}
#monthlyPaymentResult {
font-size: 28px;
font-weight: bold;
color: #28a745;
margin-bottom: 10px;
}
#totalInterestResult, #totalCostResult {
margin-top: 10px;
font-size: 16px;
color: #555;
}
#auto-loan-calculator-explanation {
margin-top: 30px;
padding-top: 20px;
border-top: 1px solid #eee;
font-size: 14px;
line-height: 1.6;
color: #444;
}
#auto-loan-calculator-explanation h3, #auto-loan-calculator-explanation h4 {
margin-top: 15px;
margin-bottom: 10px;
color: #333;
}
#auto-loan-calculator-explanation ul {
padding-left: 20px;
}
#auto-loan-calculator-explanation li {
margin-bottom: 8px;
}
#auto-loan-calculator-explanation code {
background-color: #f0f0f0;
padding: 2px 5px;
border-radius: 3px;
font-family: Consolas, Monaco, 'Andale Mono', 'Ubuntu Mono', monospace;
}