Estimate your total monthly payment including taxes, insurance, and PMI.
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$
%
$
$
$
Estimated Total Monthly Payment
$0.00
Principal, Interest, Taxes, Insurance & PMI
Payment Breakdown
Principal & Interest
$0.00
Property Taxes
$0.00
Homeowner's Insurance
$0.00
PMI (Mortgage Insurance)
$0.00
Total Loan Amount
$0.00
Total Interest Paid
$0.00
function calculateMortgage() {
// 1. Get input values using var
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 insurance = parseFloat(document.getElementById('insurance').value);
var pmi = parseFloat(document.getElementById('pmi').value);
// 2. Validation
if (isNaN(homePrice) || homePrice <= 0) { alert("Please enter a valid Home Price."); return; }
if (isNaN(downPayment) || downPayment < 0) { downPayment = 0; }
if (isNaN(interestRate) || interestRate <= 0) { alert("Please enter a valid Interest Rate."); return; }
if (isNaN(loanTerm) || loanTerm <= 0) { alert("Please enter a valid Loan Term."); return; }
if (isNaN(propertyTax) || propertyTax < 0) { propertyTax = 0; }
if (isNaN(insurance) || insurance < 0) { insurance = 0; }
if (isNaN(pmi) || pmi = home price
if (loanAmount 0) {
monthlyPI = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, numberOfPayments)) / (Math.pow(1 + monthlyRate, numberOfPayments) – 1);
} else {
monthlyPI = loanAmount / numberOfPayments;
}
var monthlyTax = propertyTax / 12;
var monthlyIns = insurance / 12;
// PMI is already monthly in input, but could be calculated as % of loan if preferred. Here we take absolute input.
var totalMonthly = monthlyPI + monthlyTax + monthlyIns + pmi;
var totalCostOfLoan = (monthlyPI * numberOfPayments);
var totalInterest = totalCostOfLoan – loanAmount;
// 4. Update UI
// Format Currency Helper
var formatter = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
minimumFractionDigits: 2
});
document.getElementById('totalMonthlyDisplay').innerHTML = formatter.format(totalMonthly);
document.getElementById('piDisplay').innerHTML = formatter.format(monthlyPI);
document.getElementById('taxDisplay').innerHTML = formatter.format(monthlyTax);
document.getElementById('insDisplay').innerHTML = formatter.format(monthlyIns);
document.getElementById('pmiDisplay').innerHTML = formatter.format(pmi);
document.getElementById('loanAmountDisplay').innerHTML = formatter.format(loanAmount);
document.getElementById('totalInterestDisplay').innerHTML = formatter.format(totalInterest);
// Show results
document.getElementById('results-area').style.display = "block";
}
Understanding Your Mortgage Payment (PITI)
Buying a home is one of the largest financial commitments most people will make. While the listing price is the headline number, your actual monthly obligation involves more than just paying back the loan. This Mortgage Payment Calculator helps you estimate your PITI—Principal, Interest, Taxes, and Insurance.
What is Included in PITI?
Lenders use PITI to determine your monthly housing expense when qualifying you for a loan. Here is the breakdown:
Principal: The portion of your payment that goes toward reducing the outstanding balance of your loan. In the early years of a mortgage, this amount is small, but it grows over time.
Interest: The cost of borrowing the money. With a standard amortization schedule, interest makes up the majority of your payment in the beginning of the loan term.
Taxes: Property taxes assessed by your local government. Lenders typically collect this monthly and hold it in an escrow account to pay the bill when it is due.
Insurance: Homeowners insurance protects the property against damage. Like taxes, this is usually escrowed into your monthly payment.
The Impact of PMI
If you put down less than 20% of the home's purchase price, lenders typically require Private Mortgage Insurance (PMI). This protects the lender if you default on the loan. PMI costs typically range from 0.5% to 1.5% of the loan amount annually, which can add hundreds of dollars to your monthly bill. This calculator allows you to input a specific monthly PMI amount to see how it affects your budget.
How Interest Rates Affect Affordability
Even a small change in interest rates can drastically alter your purchasing power. For example, on a $350,000 loan:
At 6.0% interest, the Principal & Interest payment is roughly $2,098.
At 7.0% interest, that payment jumps to $2,328.
That is a difference of $230 per month, or nearly $83,000 in extra interest over a 30-year term. Using this calculator to test different rate scenarios helps you understand exactly how market fluctuations impact your wallet.
Tips for Lowering Your Monthly Payment
Increase your down payment: This lowers the principal loan amount and may eliminate the need for PMI.
Improve your credit score: A higher credit score often qualifies you for a lower interest rate.
Shop for cheaper insurance: Insurance premiums vary wildly by provider. Shopping around can save you $20-$50 per month.
Appeal your property taxes: If you believe your home's assessed value is too high, you can appeal to your local municipality to lower your tax burden.
Using the Mortgage Calculator
To get the most accurate result, try to find the specific property tax rate for the county where you are looking to buy (usually between 1% and 2.5% of the home value) and get a quote for homeowners insurance. While the default values in the calculator provide a good baseline, inputting your specific local data will give you the confidence needed to make a smart offer.