Extra Payment Auto Loan Calculator
Calculate how extra payments can shorten your auto loan term and save you money in interest.
function calculateAutoLoan(){
const loanAmount = parseFloat(document.getElementById(“loanAmount”).value);
const interestRate = parseFloat(document.getElementById(“interestRate”).value) / 100 / 12;
const loanTerm = parseInt(document.getElementById(“loanTerm”).value) * 12;
const extraPayment = parseFloat(document.getElementById(“extraPayment”).value);
if (isNaN(loanAmount) || isNaN(interestRate) || isNaN(loanTerm) || isNaN(extraPayment) || loanAmount <= 0 || interestRate <= 0 || loanTerm <= 0 || extraPayment 0) {
const interestPayment = remainingBalance * interestRate;
const principalPayment = monthlyPayment – interestPayment + extraPayment;
remainingBalance -= principalPayment;
totalInterestPaid += interestPayment;
monthsPaid++;
}
const totalInterest = totalInterestPaid – (loanAmount * interestRate * loanTerm / 12);
const newTerm = (monthsPaid / 12).toFixed(2);
document.getElementById(“totalInterest”).value = formatCurrency(totalInterest);
document.getElementById(“newTerm”).value = newTerm;
}
function resetAutoLoan() {
document.querySelectorAll(“#calculator input”).forEach(el => el.value = “”);
}
function formatCurrency(n) {
return “$” + n.toFixed(2);
}
