Interest Mortgage Rate Calculator
function calculateMortgage() {
const loanAmount = parseFloat(document.getElementById(‘loanAmount’).value);
const interestRate = parseFloat(document.getElementById(‘interestRate’).value) / 100 / 12;
const loanTerm = parseInt(document.getElementById(‘loanTerm’).value) * 12;
if (isNaN(loanAmount) || isNaN(interestRate) || isNaN(loanTerm) || loanAmount <= 0 || interestRate <= 0 || loanTerm <= 0) {
alert('Please fill all fields with valid numbers.');
return;
}
const monthlyPayment = (loanAmount * interestRate) / (1 – Math.pow(1 + interestRate, -loanTerm));
const totalPayment = monthlyPayment * loanTerm;
const totalInterest = totalPayment – loanAmount;
document.getElementById('monthlyPayment').value = monthlyPayment.toFixed(2);
document.getElementById('totalPayment').value = totalPayment.toFixed(2);
document.getElementById('totalInterest').value = totalInterest.toFixed(2);
document.getElementById('calculationSteps').innerHTML = `
Calculation Steps:
Loan Amount: $${loanAmount.toFixed(2)}
Interest Rate: ${interestRate * 12 * 100}% annually
Loan Term: ${loanTerm / 12} years
Monthly Payment: $${monthlyPayment.toFixed(2)}
Total Payment: $${totalPayment.toFixed(2)}
Total Interest: $${totalInterest.toFixed(2)}
`;
}
