Please enter valid positive numbers for all fields.
Principal & Interest:$0.00
Property Tax:$0.00
Home Insurance:$0.00
HOA Fees:$0.00
Total Monthly Payment:$0.00
Understanding Your Mortgage Payment
Purchasing a home is one of the most significant financial decisions you will make. This Mortgage Payment Calculator helps you estimate your monthly financial commitment by breaking down the costs associated with homeownership. Unlike simple calculators that only look at the loan principal and interest, this tool factors in taxes, insurance, and HOA fees for a realistic view of your budget.
Components of a Mortgage Payment (PITI)
Real estate experts often refer to the components of a mortgage payment as PITI:
Principal: The portion of your payment that goes toward paying down the loan balance.
Interest: The cost of borrowing money from your lender. In the early years of a mortgage, the majority of your payment goes toward interest.
Taxes: Property taxes assessed by your local government, typically held in an escrow account by your lender.
Insurance: Homeowners insurance protects your property against damage and liability. This is also usually escrowed.
How Interest Rates Affect Your Payment
Even a small difference in interest rates can have a massive impact on your monthly payment and the total interest paid over the life of the loan. For example, on a $300,000 loan, the difference between a 6% and a 7% interest rate can change your monthly payment by nearly $200 and cost you tens of thousands of dollars extra over 30 years.
The Impact of the Loan Term
While a 30-year fixed-rate mortgage is the most common, opting for a 15-year term will significantly increase your monthly payment but drastically reduce the total interest you pay. Use the calculator above to compare how different terms affect your monthly budget.
Don't Forget HOA Fees
If you are buying a condo, townhouse, or a home in a planned community, you likely have to pay Homeowners Association (HOA) fees. These are separate from your mortgage but impact your debt-to-income ratio and monthly affordability. Always include these in your calculation to ensure you don't overextend your finances.
function calculateMortgage() {
// 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 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);
// Error Handling Element
var errorMsg = document.getElementById('errorMessage');
var resultsDiv = document.getElementById('results');
// Validation logic
if (isNaN(homePrice) || isNaN(downPayment) || isNaN(interestRate) || isNaN(loanTerm) || isNaN(propertyTax) || isNaN(homeInsurance) || isNaN(hoaFees) || homePrice <= 0 || loanTerm <= 0) {
errorMsg.style.display = 'block';
resultsDiv.style.display = 'none';
return;
}
errorMsg.style.display = 'none';
// Mortgage Calculation Logic
var principal = homePrice – downPayment;
var monthlyRate = (interestRate / 100) / 12;
var numberOfPayments = loanTerm * 12;
// Calculate Principal & Interest (P&I)
// Formula: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
var monthlyPrincipalAndInterest = 0;
if (interestRate === 0) {
monthlyPrincipalAndInterest = principal / numberOfPayments;
} else {
monthlyPrincipalAndInterest = principal * (monthlyRate * Math.pow(1 + monthlyRate, numberOfPayments)) / (Math.pow(1 + monthlyRate, numberOfPayments) – 1);
}
// Calculate Monthly Tax and Insurance
var monthlyTax = propertyTax / 12;
var monthlyInsurance = homeInsurance / 12;
// Calculate Total Monthly Payment
var totalMonthlyPayment = monthlyPrincipalAndInterest + monthlyTax + monthlyInsurance + hoaFees;
// Update DOM with results
document.getElementById('piResult').innerText = '$' + monthlyPrincipalAndInterest.toFixed(2).replace(/\B(?=(\d{3})+(?!\d))/g, ",");
document.getElementById('taxResult').innerText = '$' + monthlyTax.toFixed(2).replace(/\B(?=(\d{3})+(?!\d))/g, ",");
document.getElementById('insResult').innerText = '$' + monthlyInsurance.toFixed(2).replace(/\B(?=(\d{3})+(?!\d))/g, ",");
document.getElementById('hoaResult').innerText = '$' + hoaFees.toFixed(2).replace(/\B(?=(\d{3})+(?!\d))/g, ",");
document.getElementById('totalResult').innerText = '$' + totalMonthlyPayment.toFixed(2).replace(/\B(?=(\d{3})+(?!\d))/g, ",");
// Show results
resultsDiv.style.display = 'block';
}