Annuity Due
Ordinary Annuity
function calculateBAIIPlus() {
const loanAmount = parseFloat(document.getElementById(“loan-amount”).value);
const interestRate = parseFloat(document.getElementById(“interest-rate”).value) / 100 / 12;
const loanTerm = parseFloat(document.getElementById(“loan-term”).value) * 12;
const paymentType = document.getElementById(“payment-type”).value;
if (isNaN(loanAmount) || isNaN(interestRate) || isNaN(loanTerm)) {
alert(“Please fill out all fields correctly.”);
return;
}
let monthlyPayment = 0;
let totalInterest = 0;
let totalLoanPaid = 0;
if (paymentType === “annuity-due”) {
monthlyPayment = loanAmount * (interestRate / (1 – Math.pow(1 + interestRate, -loanTerm)));
} else {
monthlyPayment = loanAmount * (interestRate / (1 – Math.pow(1 + interestRate, -loanTerm)));
}
totalLoanPaid = monthlyPayment * loanTerm;
totalInterest = totalLoanPaid – loanAmount;
document.getElementById(“monthly-payment”).textContent = “$” + monthlyPayment.toFixed(2);
document.getElementById(“total-interest”).textContent = “$” + totalInterest.toFixed(2);
document.getElementById(“total-loan”).textContent = “$” + totalLoanPaid.toFixed(2);
}
