Please enter valid numbers for all required fields.
Principal & Interest:$0.00
Monthly Property Tax:$0.00
Monthly Insurance:$0.00
HOA / PMI:$0.00
Total Monthly Payment: $0.00
Understanding Your Mortgage Payment
Calculating your potential monthly mortgage payment is the first step in the home buying process. This PITI Mortgage Calculator breaks down the four critical components of your monthly housing expense: Principal, Interest, Taxes, and Insurance.
What is Included in PITI?
Principal: The portion of your payment that goes toward reducing the loan balance.
Interest: The cost of borrowing money from your lender, calculated based on your annual percentage rate (APR).
Taxes: Property taxes assessed by your local government, typically held in escrow and paid annually.
Insurance: Homeowners insurance to protect against hazards like fire and theft.
How Interest Rates Affect Affordability
Even a small change in interest rates can significantly impact your monthly payment. For example, on a $300,000 loan, a 1% increase in interest rate can raise your monthly payment by over $150. Use this tool to test different scenarios and determine a budget that keeps your finances healthy.
HOA and PMI
Don't forget to account for Homeowners Association (HOA) fees if you are buying a condo or in a planned community, and Private Mortgage Insurance (PMI) if your down payment is less than 20%. These can add hundreds of dollars to your monthly obligation.
function calculateMortgage() {
// Input Retrieval
var price = parseFloat(document.getElementById('mc_home_price').value);
var down = parseFloat(document.getElementById('mc_down_payment').value);
var rate = parseFloat(document.getElementById('mc_interest_rate').value);
var years = parseFloat(document.getElementById('mc_loan_term').value);
var taxYear = parseFloat(document.getElementById('mc_property_tax').value);
var insYear = parseFloat(document.getElementById('mc_insurance').value);
var hoaMonth = parseFloat(document.getElementById('mc_hoa').value);
// Validation
if (isNaN(price) || isNaN(down) || isNaN(rate) || isNaN(years) || isNaN(taxYear) || isNaN(insYear)) {
document.getElementById('mc_error').style.display = 'block';
document.getElementById('mc-result').style.display = 'none';
return;
}
// Handle NaN for optional HOA
if (isNaN(hoaMonth)) { hoaMonth = 0; }
document.getElementById('mc_error').style.display = 'none';
// Calculations
var principal = price – down;
var monthlyInterest = rate / 100 / 12;
var payments = years * 12;
// Monthly Principal & Interest (M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1])
var x = Math.pow(1 + monthlyInterest, payments);
var monthlyPI = (principal * x * monthlyInterest) / (x – 1);
// If interest rate is 0 (edge case)
if (rate === 0) {
monthlyPI = principal / payments;
}
var monthlyTax = taxYear / 12;
var monthlyIns = insYear / 12;
var totalMonthly = monthlyPI + monthlyTax + monthlyIns + hoaMonth;
// Output Formatting
var formatter = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
minimumFractionDigits: 2
});
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_hoa').innerHTML = formatter.format(hoaMonth);
document.getElementById('res_total').innerHTML = formatter.format(totalMonthly);
document.getElementById('mc-result').style.display = 'block';
}