Mortgage Payment Calculator with Taxes & Insurance
Calculating your potential monthly mortgage payment is one of the most critical steps in the home-buying process. Unlike simple loan calculators, a true mortgage estimation must account for the "PITI" components: Principal, Interest, Taxes, and Insurance. Our comprehensive Mortgage Payment Calculator helps you determine exactly how much home you can afford by factoring in these essential variables alongside your down payment and loan term.
Understanding the PITI Formula
When you take out a mortgage, your monthly bill covers more than just paying back the bank. Here is a breakdown of what makes up your payment:
Principal: The portion of the payment that reduces the loan balance.
Interest: The cost of borrowing money, determined by your interest rate.
Taxes: Property taxes charged by your local municipality, usually held in escrow.
Insurance: Homeowners insurance to protect your property against damage.
How Interest Rates Impact Your Payment
Even a small fluctuation in interest rates can significantly affect your monthly financial obligation. For example, on a $300,000 loan, the difference between a 6.5% and a 7.5% interest rate can amount to hundreds of dollars per month and tens of thousands over the life of the loan. Use the calculator below to test different rate scenarios to see how they impact your budget.
Principal & Interest:$0.00
Monthly Property Tax:$0.00
Monthly Insurance:$0.00
Total Monthly Payment:$0.00
Why the Down Payment Matters
Putting 20% down is the industry gold standard. It often allows you to avoid Private Mortgage Insurance (PMI), which protects the lender if you default. If you input a down payment less than 20% of the home price, keep in mind that lenders may add PMI costs on top of the figures shown above, further increasing your monthly outlay.
Frequently Asked Questions
Does this calculator include HOA fees?
Currently, this calculator focuses on PITI. If you are buying a condo or a home in a community with Homeowners Association (HOA) fees, you should add that monthly cost on top of the "Total Monthly Payment" calculated above.
What is a good debt-to-income ratio for a mortgage?
Most lenders prefer a back-end debt-to-income ratio (including your new mortgage) of 36% or less, though some programs allow for higher ratios depending on your credit score.
function calculateMortgage() {
// 1. Get Input Values
var priceInput = document.getElementById("homePrice").value;
var downInput = document.getElementById("downPayment").value;
var rateInput = document.getElementById("interestRate").value;
var termInput = document.getElementById("loanTerm").value;
var taxInput = document.getElementById("propertyTax").value;
var insInput = document.getElementById("insurance").value;
// 2. Validate Numbers
var price = parseFloat(priceInput);
var down = parseFloat(downInput);
var rate = parseFloat(rateInput);
var term = parseFloat(termInput);
var tax = parseFloat(taxInput);
var ins = parseFloat(insInput);
if (isNaN(price) || isNaN(down) || isNaN(rate) || isNaN(term) || isNaN(tax) || isNaN(ins)) {
alert("Please enter valid numbers in all fields.");
return;
}
// 3. Perform Calculations
var loanAmount = price – down;
// Convert annual rate to monthly decimal
var monthlyRate = (rate / 100) / 12;
// Convert years to months
var numberOfPayments = term * 12;
// Calculate Monthly Principal & Interest using standard amortization formula: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1]
var monthlyPI = 0;
if (rate === 0) {
monthlyPI = loanAmount / numberOfPayments;
} else {
monthlyPI = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, numberOfPayments)) / (Math.pow(1 + monthlyRate, numberOfPayments) – 1);
}
// Calculate Monthly Tax and Insurance
var monthlyTax = tax / 12;
var monthlyIns = ins / 12;
// Total
var totalMonthly = monthlyPI + monthlyTax + monthlyIns;
// 4. Update DOM with Results (formatted as Currency)
var formatter = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
});
document.getElementById("res-pi").innerHTML = formatter.format(monthlyPI);
document.getElementById("res-tax").innerHTML = formatter.format(monthlyTax);
document.getElementById("res-ins").innerHTML = formatter.format(monthlyIns);
document.getElementById("res-total").innerHTML = formatter.format(totalMonthly);
// Show the results div
document.getElementById("results-area").style.display = "block";
}