Financing a car with a loan from America First Credit Union (AFCU) or any lender involves understanding the key factors that determine your monthly payment. Our car loan calculator is designed to give you a clear estimate based on the vehicle's price, your down payment, the interest rate, and the loan term.
How the Calculator Works: The Math Behind Your Loan
The AFCU car loan calculator uses a standard loan amortization formula to estimate your monthly payment. The formula takes into account the principal loan amount, the interest rate, and the loan term.
Here's a breakdown of the calculation:
Loan Amount (Principal): This is the total price of the car minus your down payment. It's the actual amount you need to borrow.
Loan Amount = Car Price - Down Payment
Annual Interest Rate: This is the percentage charged by the lender on the outstanding loan balance. For the calculation, we convert this to a monthly rate.
Monthly Interest Rate = Annual Interest Rate / 12 / 100
Loan Term: This is the total duration of the loan, typically expressed in years. For the calculation, we convert this to the total number of monthly payments.
Total Number of Payments = Loan Term (in Years) * 12
The core formula for calculating the monthly payment (M) is:
M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1]
Where:
P = Principal Loan Amount (Loan Amount after down payment)
i = Monthly Interest Rate
n = Total Number of Payments (Loan Term in months)
If the interest rate is 0%, the calculation simplifies to:
M = P / n
Key Factors Influencing Your Monthly Payment:
Car Price: A higher car price generally means a higher loan amount and thus a higher monthly payment.
Down Payment: A larger down payment reduces the principal loan amount, lowering your monthly payments and potentially securing a better interest rate.
Interest Rate: This is one of the most significant factors. A lower Annual Percentage Rate (APR) means you pay less in interest over the life of the loan, resulting in lower monthly payments. AFCU often offers competitive rates for members.
Loan Term: A longer loan term (e.g., 72 months vs. 48 months) will result in lower monthly payments, but you will pay more interest overall. Conversely, a shorter term means higher monthly payments but less total interest paid.
Using the AFCU Car Loan Calculator:
Simply input the car's price, your intended down payment, the expected annual interest rate (APR), and the desired loan term in years. The calculator will then provide an estimate of your monthly payment. This tool is invaluable for budgeting and comparing different loan scenarios before you visit AFCU.
Remember, this is an estimate. Actual loan terms and rates may vary based on your creditworthiness and AFCU's current lending policies. We encourage you to consult directly with America First Credit Union for personalized loan offers and to discuss specific financing options.
function updateInterestRateInput() {
var slider = document.getElementById("interestRateSlider");
var input = document.getElementById("interestRate");
input.value = slider.value;
calculateCarLoan();
}
function updateLoanTermInput() {
var slider = document.getElementById("loanTermSlider");
var input = document.getElementById("loanTerm");
input.value = slider.value;
calculateCarLoan();
}
function calculateCarLoan() {
var loanAmountInput = document.getElementById("loanAmount");
var downPaymentInput = document.getElementById("downPayment");
var interestRateInput = document.getElementById("interestRate");
var loanTermInput = document.getElementById("loanTerm");
var monthlyPaymentSpan = document.getElementById("monthlyPayment");
var carPrice = parseFloat(loanAmountInput.value);
var downPayment = parseFloat(downPaymentInput.value);
var annualInterestRate = parseFloat(interestRateInput.value);
var loanTermYears = parseInt(loanTermInput.value);
// Validate inputs
if (isNaN(carPrice) || carPrice < 0) {
alert("Please enter a valid car price.");
loanAmountInput.focus();
return;
}
if (isNaN(downPayment) || downPayment carPrice) {
alert("Down payment cannot be greater than the car price.");
downPaymentInput.focus();
return;
}
if (isNaN(annualInterestRate) || annualInterestRate < 0) {
alert("Please enter a valid annual interest rate.");
interestRateInput.focus();
return;
}
if (isNaN(loanTermYears) || loanTermYears 0) {
monthlyPayment = principal * (monthlyInterestRate * Math.pow(1 + monthlyInterestRate, numberOfPayments)) / (Math.pow(1 + monthlyInterestRate, numberOfPayments) – 1);
} else {
monthlyPayment = principal / numberOfPayments;
}
// Display the result, formatted to two decimal places
if (!isNaN(monthlyPayment)) {
monthlyPaymentSpan.textContent = "$" + monthlyPayment.toFixed(2);
} else {
monthlyPaymentSpan.textContent = "$0.00";
}
}
// Initial calculation on page load
document.addEventListener("DOMContentLoaded", function() {
calculateCarLoan();
// Sync slider and input values initially
document.getElementById("interestRateSlider").value = document.getElementById("interestRate").value;
document.getElementById("loanTermSlider").value = document.getElementById("loanTerm").value;
});