Estimate your monthly payments, including taxes and insurance.
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20 Years
15 Years
10 Years
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Estimated Monthly Payment
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Principal & Interest
$0.00
Property Taxes
$0.00
Homeowners Insurance
$0.00
HOA Fees
$0.00
Total Monthly
$0.00
Loan Amount
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Total Interest Paid (Over Life of Loan)
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Understanding Your Mortgage Calculation
Buying a home is often the largest financial decision a person will make. Understanding exactly how your monthly payment is calculated is crucial for budgeting and financial planning. This Mortgage Payment Calculator helps you break down the costs associated with homeownership beyond just the sticker price of the house.
The 4 Pillars of a Mortgage Payment (PITI)
Most lenders use the acronym PITI to describe the components of a mortgage payment:
Principal: The portion of your payment that goes towards paying down the actual loan balance. In the early years of a standard 30-year mortgage, this portion is small but grows over time.
Interest: The cost of borrowing money. Initially, the majority of your payment goes toward interest. The interest rate is determined by market conditions and your creditworthiness.
Taxes: Property taxes assessed by your local government. These are typically collected by your lender in an escrow account and paid annually on your behalf.
Insurance: Homeowners insurance protects your property against damage. Like taxes, this is usually part of your monthly escrow payment.
How Interest Rates Affect Affordability
Even a small change in interest rates can significantly impact your monthly payment and the total cost of the loan. For example, on a $300,000 loan, a 1% increase in interest rate can raise your monthly payment by hundreds of dollars and cost tens of thousands more in interest over the life of the loan.
The Role of the Down Payment
Your down payment reduces the principal amount you need to borrow. A larger down payment (typically 20% or more) can help you avoid Private Mortgage Insurance (PMI), obtain a lower interest rate, and lower your monthly obligations. This calculator allows you to input your specific down payment to see how it shifts the math.
HOA Fees
If you are buying a condo or a home in a planned community, you will likely have to pay Homeowners Association (HOA) fees. These are separate from your mortgage but are a mandatory monthly cost that affects your debt-to-income ratio and overall affordability. Always include these in your calculations.
Frequently Asked Questions
What is an Amortization Schedule?
Amortization refers to the process of paying off a debt over time through regular payments. An amortization schedule is a table detailing each periodic payment on an amortizing loan. It shows the amount of principal and the amount of interest that comprise each payment until the loan is paid off at the end of its term.
Should I choose a 15-year or 30-year mortgage?
A 15-year mortgage typically comes with a lower interest rate and you will pay significantly less total interest over the life of the loan. However, the monthly payments are much higher because you are paying off the principal twice as fast. A 30-year mortgage offers lower monthly payments, providing more flexibility in your monthly budget, but costs more in interest over time.
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 loanTermYears = parseFloat(document.getElementById("loanTerm").value);
var annualTax = parseFloat(document.getElementById("propertyTax").value);
var annualInsurance = parseFloat(document.getElementById("homeInsurance").value);
var monthlyHOA = parseFloat(document.getElementById("hoaFees").value);
var errorMsg = document.getElementById("errorMsg");
var resultsSection = document.getElementById("resultsSection");
// Validation
if (isNaN(homePrice) || isNaN(downPayment) || isNaN(interestRate) || isNaN(loanTermYears) ||
isNaN(annualTax) || isNaN(annualInsurance) || isNaN(monthlyHOA) || homePrice <= 0) {
errorMsg.style.display = "block";
resultsSection.style.display = "none";
return;
}
errorMsg.style.display = "none";
// Mortgage Calculation Logic
var principal = homePrice – downPayment;
var monthlyRate = (interestRate / 100) / 12;
var numberOfPayments = loanTermYears * 12;
// P&I Calculation Formula: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
var monthlyPI = 0;
if (monthlyRate === 0) {
monthlyPI = principal / numberOfPayments;
} else {
monthlyPI = principal * (monthlyRate * Math.pow(1 + monthlyRate, numberOfPayments)) / (Math.pow(1 + monthlyRate, numberOfPayments) – 1);
}
// Calculate Components
var monthlyTax = annualTax / 12;
var monthlyInsurance = annualInsurance / 12;
var totalMonthly = monthlyPI + monthlyTax + monthlyInsurance + monthlyHOA;
var totalCostOfLoan = (monthlyPI * numberOfPayments);
var totalInterest = totalCostOfLoan – principal;
// Formatting Helper Function
function formatCurrency(num) {
return "$" + num.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
}
// Display Results
document.getElementById("totalMonthlyPayment").innerHTML = formatCurrency(totalMonthly);
document.getElementById("piAmount").innerHTML = formatCurrency(monthlyPI);
document.getElementById("taxAmount").innerHTML = formatCurrency(monthlyTax);
document.getElementById("insAmount").innerHTML = formatCurrency(monthlyInsurance);
document.getElementById("hoaAmount").innerHTML = formatCurrency(monthlyHOA);
document.getElementById("breakdownTotal").innerHTML = formatCurrency(totalMonthly);
document.getElementById("loanAmountResult").innerHTML = formatCurrency(principal);
document.getElementById("totalInterestResult").innerHTML = formatCurrency(totalInterest);
// Show Section
resultsSection.style.display = "block";
}