Please enter valid positive numbers for all fields.
Estimated Monthly Payment
$0.00
(Principal, Interest, Taxes & Insurance)
Principal & Interest
$0.00
Total Interest Paid
$0.00
Payoff Date
—
Annual Amortization Schedule
Year
Interest Paid
Principal Paid
Remaining Balance
Understanding Your Mortgage Payments
Purchasing a home is one of the most significant financial decisions you will ever make. Our Mortgage Payment Calculator is designed to provide clarity on your potential monthly obligations. By analyzing factors such as the home price, down payment, interest rate, and loan term, this tool helps you visualize exactly where your money goes every month.
Key Components of a Mortgage Payment
Your monthly payment is typically referred to as PITI (Principal, Interest, Taxes, and Insurance). Understanding these four components is crucial for accurate budgeting:
Principal: This is the portion of your payment that goes directly toward paying down the loan balance. In the early years of a mortgage, this amount is small, but it increases over time.
Interest: This is the cost of borrowing money from your lender. Initially, interest makes up the majority of your monthly payment.
Taxes: Property taxes are assessed by your local government and are often bundled into your monthly mortgage payment through an escrow account.
Insurance: Lenders require homeowners insurance to protect the property against damage. Like taxes, this is often paid monthly into escrow.
How Interest Rates Impact Your Loan
Even a small difference in your interest rate can have a massive impact on the total cost of your home. For example, on a $300,000 loan, the difference between a 4% and a 5% interest rate can amount to tens of thousands of dollars in extra interest over a 30-year term. Use this calculator to experiment with different rates and see how refinancing or shopping for a better rate could save you money.
What is Amortization?
Amortization is the process of spreading out a loan into a series of fixed payments over time. While your total monthly payment remains the same (assuming a fixed-rate mortgage), the ratio of principal to interest changes with every payment.
As shown in the amortization schedule generated by our calculator above, your early payments are primarily interest. As the loan matures, you start paying down more principal, building equity in your home faster. This schedule allows you to see exactly how much equity you will have built at any specific year in the future.
Frequently Asked Questions (FAQ)
Should I put 20% down?
Putting 20% down helps you avoid Private Mortgage Insurance (PMI), which is an extra cost added to your monthly bill to protect the lender. However, many loan programs allow for lower down payments.
How does the loan term affect my payment?
A shorter loan term (e.g., 15 years) will result in higher monthly payments but significantly less total interest paid over the life of the loan. A longer term (e.g., 30 years) lowers the monthly payment but increases the total interest cost.
function calculateMortgage() {
// 1. Get Input Values
var priceInput = document.getElementById('mc_home_price').value;
var downInput = document.getElementById('mc_down_payment').value;
var rateInput = document.getElementById('mc_interest_rate').value;
var termInput = document.getElementById('mc_loan_term').value;
var taxInput = document.getElementById('mc_property_tax').value;
var insuranceInput = document.getElementById('mc_home_insurance').value;
// 2. Validate Inputs
// Convert to numbers
var price = parseFloat(priceInput);
var down = parseFloat(downInput);
var rate = parseFloat(rateInput);
var term = parseFloat(termInput);
var taxYearly = parseFloat(taxInput);
var insuranceYearly = parseFloat(insuranceInput);
// Handle optional fields being empty (treat as 0)
if (isNaN(taxYearly)) taxYearly = 0;
if (isNaN(insuranceYearly)) insuranceYearly = 0;
var errorMsg = document.getElementById('mc_error');
var resultsDiv = document.getElementById('mc_results');
// Check basic validity
if (isNaN(price) || isNaN(down) || isNaN(rate) || isNaN(term) || price <= 0 || term <= 0) {
errorMsg.style.display = 'block';
resultsDiv.style.display = 'none';
return;
} else {
errorMsg.style.display = 'none';
}
// 3. Calculation Logic
var loanAmount = price – down;
// If down payment is greater than price
if (loanAmount < 0) {
loanAmount = 0;
}
// Monthly Interest Rate
var monthlyRate = (rate / 100) / 12;
// Total Number of Payments
var totalPayments = term * 12;
// Monthly Principal & Interest Payment Formula: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1]
var monthlyPI = 0;
if (monthlyRate === 0) {
monthlyPI = loanAmount / totalPayments;
} else {
monthlyPI = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, totalPayments)) / (Math.pow(1 + monthlyRate, totalPayments) – 1);
}
if (isNaN(monthlyPI) || !isFinite(monthlyPI)) {
monthlyPI = 0;
}
// Taxes and Insurance Monthly
var monthlyTax = taxYearly / 12;
var monthlyIns = insuranceYearly / 12;
var totalMonthlyPayment = monthlyPI + monthlyTax + monthlyIns;
var totalCost = (monthlyPI * totalPayments);
var totalInterest = totalCost – loanAmount;
// Calculate Payoff Date
var today = new Date();
var payoffYear = today.getFullYear() + term;
var payoffMonth = today.toLocaleString('default', { month: 'short' });
// 4. Update UI
// Helper for currency format
var formatter = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
minimumFractionDigits: 2
});
document.getElementById('mc_total_monthly').innerHTML = formatter.format(totalMonthlyPayment);
document.getElementById('mc_pi_monthly').innerHTML = formatter.format(monthlyPI);
document.getElementById('mc_total_interest').innerHTML = formatter.format(totalInterest);
document.getElementById('mc_payoff_date').innerHTML = payoffMonth + " " + payoffYear;
resultsDiv.style.display = 'block';
// 5. Generate Amortization Schedule (Yearly aggregation)
var tbody = document.getElementById('mc_amortization_body');
tbody.innerHTML = ''; // Clear previous
var balance = loanAmount;
var yearInterest = 0;
var yearPrincipal = 0;
var currentYear = 1;
for (var i = 1; i <= totalPayments; i++) {
var interestPayment = balance * monthlyRate;
var principalPayment = monthlyPI – interestPayment;
if (balance < principalPayment) {
principalPayment = balance; // Pay off remainder
}
balance -= principalPayment;
yearInterest += interestPayment;
yearPrincipal += principalPayment;
// End of year or end of loan
if (i % 12 === 0 || balance 0 ? balance : 0);
row.appendChild(cellYear);
row.appendChild(cellInt);
row.appendChild(cellPrin);
row.appendChild(cellBal);
tbody.appendChild(row);
// Reset yearly counters
yearInterest = 0;
yearPrincipal = 0;
currentYear++;
if (balance <= 0.1) break;
}
}
}