Estimate your monthly payments and total loan costs.
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Please enter valid positive numbers.
Estimated Monthly Payment
$0.00
Principal & Interest$0.00
Property Tax$0.00
Home Insurance$0.00
HOA Fees$0.00
Loan Amount$0.00
Total Interest Paid$0.00
Understanding Your Mortgage Payment
Buying a home is one of the most significant financial decisions you will ever make. Understanding how your mortgage payment is calculated is crucial for budgeting and financial planning. Our Mortgage Calculator is designed to provide a clear breakdown of your monthly obligations, helping you determine exactly "how much house" you can afford.
The 4 Pillars of a Mortgage Payment (PITI)
Most monthly mortgage payments consist of four main components, often referred to by the acronym PITI:
Principal: The portion of your payment that goes toward paying down the loan balance. In the early years of a mortgage, this amount is small, but it increases over time.
Interest: The cost of borrowing money from your lender. This makes up the majority of your payment in the early years of a long-term loan.
Taxes: Property taxes assessed by your local government. These are typically collected by the lender in an escrow account and paid annually on your behalf.
Insurance: Homeowners insurance protects your property against hazards like fire and theft. Like taxes, this is usually part of your monthly escrow payment.
How Interest Rates Impact Your Buying Power
Even a small change in interest rates can dramatically affect your monthly payment and the total cost of your loan. For example, on a $300,000 loan, the difference between a 6% and a 7% interest rate can increase your monthly payment by nearly $200 and cost you tens of thousands of dollars more in interest over the life of a 30-year 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), secure a lower interest rate, and significantly lower your monthly principal and interest payments.
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 intend to pay upfront.
Interest Rate: current market rates for your credit score profile.
Loan Term: The duration of the loan, typically 15 or 30 years.
Taxes & Insurance: Estimates for local property tax rates and insurance premiums.
Input these figures into the fields above to see a detailed breakdown of your estimated monthly housing costs.
function calculateMortgage() {
// Get Input Elements
var homePriceInput = document.getElementById("homePrice");
var downPaymentInput = document.getElementById("downPayment");
var loanTermInput = document.getElementById("loanTerm");
var interestRateInput = document.getElementById("interestRate");
var propertyTaxInput = document.getElementById("propertyTax");
var insuranceInput = document.getElementById("insurance");
var hoaFeesInput = document.getElementById("hoaFees");
// Parse Values
var price = parseFloat(homePriceInput.value);
var down = parseFloat(downPaymentInput.value);
var years = parseFloat(loanTermInput.value);
var rate = parseFloat(interestRateInput.value);
var taxYearly = parseFloat(propertyTaxInput.value);
var insuranceYearly = parseFloat(insuranceInput.value);
var hoaMonthly = parseFloat(hoaFeesInput.value);
// Validation
if (isNaN(price) || isNaN(down) || isNaN(years) || isNaN(rate) ||
isNaN(taxYearly) || isNaN(insuranceYearly) || isNaN(hoaMonthly) ||
price < 0 || years <= 0) {
document.getElementById("errorMsg").style.display = "block";
document.getElementById("results").style.display = "none";
return;
}
document.getElementById("errorMsg").style.display = "none";
// Logic
var loanAmount = price – down;
// Handle negative loan amount
if (loanAmount < 0) {
loanAmount = 0;
}
var monthlyRate = (rate / 100) / 12;
var numPayments = years * 12;
var monthlyPrincipalInterest = 0;
// Mortgage Formula: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
if (rate === 0) {
monthlyPrincipalInterest = loanAmount / numPayments;
} else {
monthlyPrincipalInterest = loanAmount *
(monthlyRate * Math.pow(1 + monthlyRate, numPayments)) /
(Math.pow(1 + monthlyRate, numPayments) – 1);
}
// Additional Monthly Costs
var monthlyTax = taxYearly / 12;
var monthlyInsurance = insuranceYearly / 12;
var totalMonthlyPayment = monthlyPrincipalInterest + monthlyTax + monthlyInsurance + hoaMonthly;
var totalInterest = (monthlyPrincipalInterest * numPayments) – loanAmount;
if (loanAmount === 0) {
totalInterest = 0;
monthlyPrincipalInterest = 0;
}
// Formatting Helper
function formatCurrency(num) {
return "$" + num.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
}
// Display Results
document.getElementById("monthlyPaymentResult").innerHTML = formatCurrency(totalMonthlyPayment);
document.getElementById("piResult").innerHTML = formatCurrency(monthlyPrincipalInterest);
document.getElementById("taxResult").innerHTML = formatCurrency(monthlyTax);
document.getElementById("insResult").innerHTML = formatCurrency(monthlyInsurance);
document.getElementById("hoaResult").innerHTML = formatCurrency(hoaMonthly);
document.getElementById("loanAmountResult").innerHTML = formatCurrency(loanAmount);
document.getElementById("totalInterestResult").innerHTML = formatCurrency(totalInterest);
// Show Results Container
document.getElementById("results").style.display = "block";
}