Estimate your monthly payments including principal, interest, taxes, and insurance.
$
$
%
Years
$
$
$
Total Monthly Payment
Principal & Interest
Total Interest Paid
Loan Payoff Date
Monthly Payment Breakdown
Principal & Interest:
Property Taxes:
Homeowners Insurance:
HOA Fees:
Understanding Your Mortgage Payment
Purchasing a home is one of the most significant financial decisions you will make. This Mortgage Calculator helps you break down your monthly expenses to ensure you can afford your dream home. It calculates not just the loan repayment, but also the additional carrying costs that are often overlooked.
What is Included in PITI?
PITI stands for Principal, Interest, Taxes, and Insurance. These are the four main components of a monthly mortgage payment:
Principal: The portion of your payment that reduces the loan balance.
Interest: The cost of borrowing money, paid to the lender. In the early years of a mortgage, a larger portion of your payment goes toward interest.
Taxes: Property taxes assessed by your local government, typically collected by the lender in an escrow account.
Insurance: Homeowners insurance protects your property against damage. Lenders require this to protect their investment.
How Interest Rates Affect Affordability
Even a small change in interest rates can have a massive impact on your monthly payment and total loan cost. For example, on a $300,000 loan, a 1% increase in interest rate can increase your monthly payment by over $180 and cost you nearly $65,000 more in total interest over a 30-year term.
Using This Calculator for Budgeting
Use the optional fields for Property Tax, Home Insurance, and HOA fees to get a realistic picture of your "out-the-door" monthly housing costs. Many buyers only look at the loan payment and are surprised by the additional $400-$800/month in taxes and insurance.
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 annualIns = parseFloat(document.getElementById('homeInsurance').value);
var monthlyHOA = parseFloat(document.getElementById('hoaFees').value);
// Validation
if (isNaN(homePrice) || isNaN(downPayment) || isNaN(interestRate) || isNaN(loanTermYears)) {
alert("Please enter valid numbers for the required fields.");
return;
}
// Core Calculations
var loanAmount = homePrice – downPayment;
var monthlyInterestRate = (interestRate / 100) / 12;
var totalPayments = loanTermYears * 12;
var monthlyPrincipalInterest = 0;
// Handle 0% interest case
if (interestRate === 0) {
monthlyPrincipalInterest = loanAmount / totalPayments;
} else {
// Standard Amortization Formula: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
var x = Math.pow(1 + monthlyInterestRate, totalPayments);
monthlyPrincipalInterest = (loanAmount * x * monthlyInterestRate) / (x – 1);
}
// Monthly Tax and Insurance
var monthlyTax = annualTax / 12;
var monthlyIns = annualIns / 12;
// Total Monthly Payment
var totalMonthlyPayment = monthlyPrincipalInterest + monthlyTax + monthlyIns + monthlyHOA;
// Total Cost Calculations
var totalCostOfLoan = (monthlyPrincipalInterest * totalPayments);
var totalInterestPaid = totalCostOfLoan – loanAmount;
// Payoff Date
var today = new Date();
var payoffDate = new Date(today.setMonth(today.getMonth() + totalPayments));
var monthNames = ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"];
var dateString = monthNames[payoffDate.getMonth()] + " " + payoffDate.getFullYear();
// Display Results
document.getElementById('resultsArea').style.display = 'block';
// Formatter
var currencyFormat = new Intl.NumberFormat('en-US', { style: 'currency', currency: 'USD' });
document.getElementById('totalMonthly').innerHTML = currencyFormat.format(totalMonthlyPayment);
document.getElementById('piMonthly').innerHTML = currencyFormat.format(monthlyPrincipalInterest);
document.getElementById('totalInterest').innerHTML = currencyFormat.format(totalInterestPaid);
document.getElementById('payoffDate').innerHTML = dateString;
// Breakdown Display
document.getElementById('bdPrincipal').innerHTML = currencyFormat.format(monthlyPrincipalInterest);
document.getElementById('bdTax').innerHTML = currencyFormat.format(monthlyTax);
document.getElementById('bdIns').innerHTML = currencyFormat.format(monthlyIns);
document.getElementById('bdHOA').innerHTML = currencyFormat.format(monthlyHOA);
// Scroll to results
document.getElementById('resultsArea').scrollIntoView({behavior: 'smooth'});
}