Amortization Results:
Monthly Payment:
Total Interest Paid:
Loan Paid Off in: years
function calculateAmortization() {
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)) {
alert(“Please enter valid values.”);
return;
}
// Monthly payment calculation
const monthlyPayment = (loanAmount * interestRate) / (1 – Math.pow(1 + interestRate, -loanTerm));
const totalMonthlyPayment = monthlyPayment + extraPayment;
// Calculate loan payoff time and interest
let remainingBalance = loanAmount;
let monthsToPayOff = 0;
let totalInterest = 0;
while (remainingBalance > 0) {
let interestPayment = remainingBalance * interestRate;
let principalPayment = totalMonthlyPayment – interestPayment;
remainingBalance -= principalPayment;
totalInterest += interestPayment;
monthsToPayOff++;
if (remainingBalance < 0) remainingBalance = 0;
}
const totalPaid = monthsToPayOff * totalMonthlyPayment;
const yearsToPayOff = monthsToPayOff / 12;
// Update results
document.getElementById('monthlyPayment').textContent = `$${totalMonthlyPayment.toFixed(2)}`;
document.getElementById('totalInterest').textContent = `$${totalInterest.toFixed(2)}`;
document.getElementById('loanTermWithExtra').textContent = yearsToPayOff.toFixed(2);
}
function resetAmortization() {
document.getElementById('amortization-form').reset();
document.getElementById('amortization-result').style.display = 'none';
}
