Estimate your monthly mortgage payments effectively by accounting for interest, taxes, insurance, and HOA fees. Use our calculator to determine exactly how much house you can afford.
30 Years
20 Years
15 Years
10 Years
Payment Breakdown
Principal & Interest:$0.00
Monthly Property Tax:$0.00
Monthly Home Insurance:$0.00
Monthly HOA Fees:$0.00
Total Monthly Payment:$0.00
Total Loan Amount: $0.00 | Total Interest Paid: $0.00
Understanding Your Mortgage Payment
When calculating your monthly mortgage costs, it is essential to look beyond just the principal and interest. Lenders often refer to your total payment as PITI, which stands for Principal, Interest, Taxes, and Insurance. This calculator helps you see the complete picture by including these critical variables.
Components of a Mortgage Payment
Principal: The portion of your payment that reduces the loan balance. In the early years of a 30-year mortgage, this amount is small compared to the interest.
Interest: The cost of borrowing money. Higher interest rates significantly increase both your monthly payment and the total cost of the loan over time.
Property Taxes: Taxes assessed by your local government based on the value of your property. These are typically divided by 12 and paid monthly into an escrow account.
Homeowners Insurance: Protection against fire, theft, and other damages. Like taxes, this is usually paid monthly through escrow.
HOA Fees: If you buy a condo or a home in a planned community, you may owe Homeowners Association fees. These are paid directly to the association but affect your monthly affordability.
How the Loan Term Affects Payments
The length of your loan term has a dramatic impact on your finances. A 30-year fixed-rate mortgage offers lower monthly payments, making homes more affordable, but you will pay significantly more in interest over the life of the loan. A 15-year mortgage will have higher monthly payments, but you will build equity much faster and save thousands of dollars in interest.
Why Use a Mortgage Calculator?
Using a specialized mortgage calculator allows you to test different scenarios before speaking with a lender. By adjusting the down payment, interest rate, or home price, you can determine a budget that fits your financial goals without becoming "house poor." Remember to factor in maintenance costs and emergency savings alongside these mortgage calculations.
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 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);
// 2. Validation / Default handling
if (isNaN(homePrice) || homePrice <= 0) homePrice = 0;
if (isNaN(downPayment) || downPayment < 0) downPayment = 0;
if (isNaN(interestRate) || interestRate < 0) interestRate = 0;
if (isNaN(propertyTax) || propertyTax < 0) propertyTax = 0;
if (isNaN(homeInsurance) || homeInsurance < 0) homeInsurance = 0;
if (isNaN(hoaFees) || hoaFees < 0) hoaFees = 0;
// 3. Logic for Principal & Interest
var principal = homePrice – downPayment;
// Handle case where down payment exceeds home price
if (principal 0 && interestRate > 0) {
// Standard Amortization Formula: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
var x = Math.pow(1 + monthlyInterestRate, numberOfPayments);
monthlyPI = principal * ((monthlyInterestRate * x) / (x – 1));
} else if (principal > 0 && interestRate === 0) {
// No interest case
monthlyPI = principal / numberOfPayments;
}
// 4. Calculate Taxes and Insurance (Monthly)
var monthlyTax = propertyTax / 12;
var monthlyInsurance = homeInsurance / 12;
// 5. Total Monthly Payment
var totalMonthlyPayment = monthlyPI + monthlyTax + monthlyInsurance + hoaFees;
// 6. Total Interest and Total Cost logic
var totalCostOfLoan = monthlyPI * numberOfPayments;
var totalInterest = totalCostOfLoan – principal;
if (principal <= 0) {
totalInterest = 0;
totalCostOfLoan = 0;
}
// 7. Format Output (Currency)
var formatter = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
minimumFractionDigits: 2
});
// 8. Update the DOM
document.getElementById("res-pi").innerHTML = formatter.format(monthlyPI);
document.getElementById("res-tax").innerHTML = formatter.format(monthlyTax);
document.getElementById("res-ins").innerHTML = formatter.format(monthlyInsurance);
document.getElementById("res-hoa").innerHTML = formatter.format(hoaFees);
document.getElementById("res-total").innerHTML = formatter.format(totalMonthlyPayment);
document.getElementById("res-loan-amount").innerHTML = formatter.format(principal);
document.getElementById("res-total-interest").innerHTML = formatter.format(totalInterest);
// Show results area
document.getElementById("results-area").style.display = "block";
}