Estimate your monthly house payments with taxes and insurance
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Years
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Please enter valid positive numbers for all fields.
Estimated Monthly Payment
$0.00
Principal & Interest
$0.00
Property Tax
$0.00
Home Insurance
$0.00
HOA Fees
$0.00
Total Loan Amount
$0.00
Payoff Date
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Understanding Your Mortgage Payment
Buying a home is one of the most significant financial decisions you will make. Understanding how your monthly mortgage payment is calculated is crucial for budgeting and determining "how much house" you can afford. This calculator breaks down the four main components of a typical mortgage payment: Principal, Interest, Taxes, and Insurance (often referred to as PITI).
1. Principal
The principal is the amount of money you borrowed to buy the home. If you bought a home for $400,000 and put $80,000 down, your starting principal is $320,000. Each month, a portion of your payment goes toward reducing this balance.
2. Interest
Interest is the fee the lender charges for loaning you the money. In the early years of a standard 30-year fixed-rate mortgage, the majority of your monthly payment goes toward interest, not principal. As the loan matures, this flips, and more of your payment pays down the principal.
3. Taxes and Insurance
Most lenders require you to pay a portion of your annual property taxes and homeowners insurance each month into an escrow account.
Property Taxes: Assessed by your local government based on the value of your property.
Homeowners Insurance: Protects your home against damages like fire, theft, or storms.
4. HOA Fees
If you buy a condo or a home in a planned community, you may owe Homeowners Association (HOA) dues. While these are usually paid directly to the association rather than the lender, they are a mandatory monthly cost that impacts your overall affordability.
How to Use This Mortgage Calculator
To get the most accurate estimate, gather the following information:
Home Price: The purchase price of the property.
Down Payment: The cash you pay upfront. A higher down payment reduces your loan amount and monthly payment.
Interest Rate: Your expected annual interest rate. Check current market rates for accuracy.
Loan Term: Typically 15 or 30 years. Shorter terms have higher monthly payments but lower total interest costs.
function calculateMortgage() {
// 1. Get input values
var homePrice = parseFloat(document.getElementById('homePrice').value);
var downPayment = parseFloat(document.getElementById('downPayment').value);
var interestRate = parseFloat(document.getElementById('interestRate').value);
var loanTermYears = parseFloat(document.getElementById('loanTerm').value);
var propertyTaxAnnual = parseFloat(document.getElementById('propertyTax').value);
var homeInsuranceAnnual = parseFloat(document.getElementById('homeInsurance').value);
var hoaFeesMonthly = parseFloat(document.getElementById('hoaFees').value);
// 2. Validate inputs
var errorMsg = document.getElementById('errorMsg');
if (isNaN(homePrice) || isNaN(downPayment) || isNaN(interestRate) ||
isNaN(loanTermYears) || isNaN(propertyTaxAnnual) ||
isNaN(homeInsuranceAnnual) || isNaN(hoaFeesMonthly) ||
homePrice < 0 || loanTermYears <= 0) {
errorMsg.style.display = 'block';
document.getElementById('resultsArea').classList.remove('active');
return;
} else {
errorMsg.style.display = 'none';
}
// 3. Core Calculations
var loanAmount = homePrice – downPayment;
// Handle case where down payment is greater than home price
if (loanAmount 0) {
if (monthlyRate === 0) {
monthlyPI = loanAmount / numberOfPayments;
} else {
// Formula: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
monthlyPI = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, numberOfPayments)) / (Math.pow(1 + monthlyRate, numberOfPayments) – 1);
}
}
// Calculate Monthly Taxes and Insurance
var monthlyTax = propertyTaxAnnual / 12;
var monthlyInsurance = homeInsuranceAnnual / 12;
// Total Monthly Payment
var totalMonthly = monthlyPI + monthlyTax + monthlyInsurance + hoaFeesMonthly;
// Calculate Payoff Date
var today = new Date();
var payoffDate = new Date(today.setMonth(today.getMonth() + numberOfPayments));
var options = { month: 'long', year: 'numeric' };
var payoffDateString = payoffDate.toLocaleDateString('en-US', options);
// 4. Update the DOM with formatted results
var formatter = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
minimumFractionDigits: 2
});
document.getElementById('piResult').innerText = formatter.format(monthlyPI);
document.getElementById('taxResult').innerText = formatter.format(monthlyTax);
document.getElementById('insResult').innerText = formatter.format(monthlyInsurance);
document.getElementById('hoaResult').innerText = formatter.format(hoaFeesMonthly);
document.getElementById('totalLoanResult').innerText = formatter.format(loanAmount);
document.getElementById('totalMonthlyPayment').innerText = formatter.format(totalMonthly);
document.getElementById('payoffDateResult').innerText = payoffDateString;
// Show results area
document.getElementById('resultsArea').classList.add('active');
}