Calculate monthly payments with Taxes, Insurance, and HOA
30 Years
20 Years
15 Years
10 Years
* PMI is automatically calculated if down payment < 20%.
Monthly Payment Breakdown
Principal & Interest:$0.00
Property Tax:$0.00
Home Insurance:$0.00
HOA Fees:$0.00
PMI (Mortgage Insurance):$0.00
Total Monthly Payment:$0.00
Loan Summary
Loan Amount:$0.00
Total Interest Paid:$0.00
Total Cost of Loan:$0.00
function calculateMortgage() {
// Retrieve inputs
var homePrice = parseFloat(document.getElementById('homePrice').value);
var downPayment = parseFloat(document.getElementById('downPayment').value);
var interestRate = parseFloat(document.getElementById('interestRate').value);
var loanTerm = parseFloat(document.getElementById('loanTerm').value);
var propertyTax = parseFloat(document.getElementById('propertyTax').value);
var homeInsurance = parseFloat(document.getElementById('homeInsurance').value);
var hoaFees = parseFloat(document.getElementById('hoaFees').value);
// Validation to prevent NaN errors
if (isNaN(homePrice) || homePrice <= 0) homePrice = 0;
if (isNaN(downPayment) || downPayment < 0) downPayment = 0;
if (isNaN(interestRate) || interestRate < 0) interestRate = 0;
if (isNaN(loanTerm)) loanTerm = 30;
if (isNaN(propertyTax)) propertyTax = 0;
if (isNaN(homeInsurance)) homeInsurance = 0;
if (isNaN(hoaFees)) hoaFees = 0;
// Core Calculation Logic
var loanAmount = homePrice – downPayment;
var monthlyRate = (interestRate / 100) / 12;
var totalMonths = loanTerm * 12;
var monthlyPI = 0;
// Handle zero interest case or standard case
if (interestRate === 0) {
monthlyPI = loanAmount / totalMonths;
} else {
// Formula: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
monthlyPI = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, totalMonths)) / (Math.pow(1 + monthlyRate, totalMonths) – 1);
}
// Validate if result is finite (avoids division by zero issues)
if (!isFinite(monthlyPI)) monthlyPI = 0;
// Monthly breakdown components
var monthlyTax = propertyTax / 12;
var monthlyIns = homeInsurance / 12;
// PMI Calculation (Simple assumption: 0.5% of loan amount annually if down payment 0 && downPaymentPercent < 20) {
pmi = (loanAmount * 0.005) / 12;
document.getElementById('pmiRow').style.display = 'flex';
} else {
document.getElementById('pmiRow').style.display = 'none';
}
var totalMonthly = monthlyPI + monthlyTax + monthlyIns + hoaFees + pmi;
var totalPaymentOverLife = (monthlyPI * totalMonths);
var totalInterest = totalPaymentOverLife – loanAmount;
var totalCost = totalPaymentOverLife + (monthlyTax * totalMonths) + (monthlyIns * totalMonths) + (hoaFees * totalMonths) + (pmi * totalMonths); // Rough estimate for total cost including escrow
// Formatting Helper
var formatter = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
minimumFractionDigits: 2
});
// Update DOM
document.getElementById('resPI').innerText = formatter.format(monthlyPI);
document.getElementById('resTax').innerText = formatter.format(monthlyTax);
document.getElementById('resIns').innerText = formatter.format(monthlyIns);
document.getElementById('resHOA').innerText = formatter.format(hoaFees);
document.getElementById('resPMI').innerText = formatter.format(pmi);
document.getElementById('resTotal').innerText = formatter.format(totalMonthly);
document.getElementById('resLoanAmount').innerText = formatter.format(loanAmount);
document.getElementById('resTotalInterest').innerText = formatter.format(totalInterest);
document.getElementById('resTotalCost').innerText = formatter.format(totalPaymentOverLife); // Showing principal + interest total
// Show results
document.getElementById('results').style.display = 'block';
}
Understanding Your Mortgage Payment Components
When you are planning to buy a home, knowing the sticker price is just the beginning. Most homebuyers focus on the principal and interest, but a true PITI (Principal, Interest, Taxes, and Insurance) calculation is essential for understanding your actual monthly financial commitment. Our comprehensive mortgage calculator breaks down these costs to give you a realistic view of your budget.
1. Principal and Interest
This is the core of your mortgage payment. The Principal is the money that goes towards paying down your loan balance, increasing your home equity. The Interest is the cost of borrowing that money, paid to the lender. In the early years of a 30-year fixed mortgage, the majority of your payment goes toward interest, while in later years, more goes toward the principal.
2. Property Taxes
Property taxes are levied by your local government to fund public services like schools, roads, and emergency services. These are typically calculated as a percentage of your home's assessed value. Lenders often collect this monthly and hold it in an escrow account to pay the tax bill when it's due. In high-tax areas, this can significantly increase your monthly outlay.
3. Homeowners Insurance & PMI
Homeowners Insurance protects your property against damage from fire, theft, and storms. Like taxes, this is usually paid monthly into escrow. If your down payment is less than 20% of the home price, you will likely also pay Private Mortgage Insurance (PMI). PMI protects the lender if you default on the loan. Our calculator automatically estimates PMI if your down payment is under the 20% threshold.
4. HOA Fees
If you are buying a condo or a home in a planned community, you may have to pay Homeowners Association (HOA) fees. These cover common area maintenance, amenities, and sometimes utilities. While HOA fees are usually paid directly to the association rather than the lender, they are a critical part of your monthly housing budget and are included in this calculator for accuracy.
How Interest Rates Affect Your Buying Power
Even a small change in interest rates can have a massive impact on your monthly payment and the total cost of the loan. For example, on a $350,000 loan, a 1% increase in interest rate can increase your monthly payment by over $200 and cost you tens of thousands of dollars in additional interest over the life of the loan. Use the calculator above to experiment with different rates and see how they impact your affordability.