Estimate your monthly mortgage payments including taxes and insurance.
30 Years
20 Years
15 Years
10 Years
Principal & Interest:$0.00
Property Tax (Monthly):$0.00
Home Insurance (Monthly):$0.00
HOA Fees (Monthly):$0.00
Total Monthly Payment:$0.00
Understanding Your Mortgage Calculation
Purchasing a home is one of the most significant financial decisions you will make. Our Mortgage Payment Calculator is designed to help you navigate this complex process by providing a clear breakdown of what you can expect to pay each month. Unlike simple calculators that only look at the loan principal and interest, this tool accounts for the "hidden" costs of homeownership: property taxes, insurance, and HOA fees.
How is Your Monthly Payment Calculated?
The total monthly payment is typically composed of four main parts, 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 grows over time.
Interest: The cost of borrowing money from your lender. This is calculated based on your annual interest rate and the remaining loan balance.
Taxes: Property taxes assessed by your local government. These are usually divided by 12 and collected monthly by your lender to be held in an escrow account.
Insurance: Homeowners insurance protects your property against damage. Like taxes, this annual premium is typically divided into monthly installments.
Factors That Impact Your Mortgage
Several variables can significantly alter your monthly payment:
Interest Rate
Even a small difference in your interest rate can save or cost you thousands of dollars over the life of the loan. A lower rate reduces your monthly interest obligation, allowing more of your payment to go toward the principal.
Loan Term
The term is the length of time you have to repay the loan. A 30-year term usually offers lower monthly payments but results in higher total interest costs. A 15-year term has higher monthly payments but allows you to build equity much faster and save significantly on interest.
Down Payment
Putting more money down upfront reduces the loan amount (the principal), which lowers your monthly principal and interest payment. Additionally, if you put down less than 20%, you may be required to pay Private Mortgage Insurance (PMI), which would further increase your monthly costs.
Frequently Asked Questions
What is an escrow account?
An escrow account is a savings account managed by your mortgage servicer. Your monthly payments for taxes and insurance are deposited here, and the servicer pays the bills when they are due.
Does this calculator include PMI?
This calculator focuses on Principal, Interest, Taxes, Insurance, and HOA. If your down payment is under 20%, you should budget an additional 0.5% to 1% of the loan amount annually for PMI.
function calculateMortgage() {
// 1. Get input values
var priceStr = document.getElementById("homePrice").value;
var downStr = document.getElementById("downPayment").value;
var rateStr = document.getElementById("interestRate").value;
var termStr = document.getElementById("loanTerm").value;
var taxStr = document.getElementById("propertyTax").value;
var insStr = document.getElementById("homeInsurance").value;
var hoaStr = document.getElementById("hoaFees").value;
// 2. Parse values to numbers
var price = parseFloat(priceStr);
var down = parseFloat(downStr);
var rate = parseFloat(rateStr);
var term = parseFloat(termStr);
var annualTax = parseFloat(taxStr);
var annualIns = parseFloat(insStr);
var monthlyHOA = parseFloat(hoaStr);
// 3. Validation
if (isNaN(price) || price <= 0) {
alert("Please enter a valid Home Price.");
return;
}
if (isNaN(down) || down < 0) {
down = 0;
}
if (isNaN(rate) || rate < 0) {
alert("Please enter a valid Interest Rate.");
return;
}
if (isNaN(term) || term <= 0) {
term = 30; // Default fallback
}
if (isNaN(annualTax)) annualTax = 0;
if (isNaN(annualIns)) annualIns = 0;
if (isNaN(monthlyHOA)) monthlyHOA = 0;
// 4. Core Calculations
var loanAmount = price – down;
if (loanAmount <= 0) {
alert("Down payment cannot be greater than or equal to Home Price.");
return;
}
var monthlyRate = rate / 100 / 12;
var numberOfPayments = term * 12;
var monthlyPI = 0;
// Handle 0% interest edge case
if (rate === 0) {
monthlyPI = loanAmount / numberOfPayments;
} else {
// Mortgage Formula: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
monthlyPI = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, numberOfPayments)) / (Math.pow(1 + monthlyRate, numberOfPayments) – 1);
}
var monthlyTax = annualTax / 12;
var monthlyIns = annualIns / 12;
var totalMonthly = monthlyPI + monthlyTax + monthlyIns + monthlyHOA;
// 5. Update UI
// Helper function for currency format
var formatCurrency = function(num) {
return "$" + num.toLocaleString('en-US', { minimumFractionDigits: 2, maximumFractionDigits: 2 });
};
document.getElementById("resPI").innerHTML = formatCurrency(monthlyPI);
document.getElementById("resTax").innerHTML = formatCurrency(monthlyTax);
document.getElementById("resIns").innerHTML = formatCurrency(monthlyIns);
document.getElementById("resHOA").innerHTML = formatCurrency(monthlyHOA);
document.getElementById("resTotal").innerHTML = formatCurrency(totalMonthly);
// Show results
document.getElementById("resultsArea").style.display = "block";
}