Mortgage Payment Calculator with Taxes, Insurance & PMI
.mpc-calculator-widget {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
max-width: 800px;
margin: 20px auto;
padding: 30px;
background: #ffffff;
border: 1px solid #e0e0e0;
border-radius: 8px;
box-shadow: 0 4px 12px rgba(0,0,0,0.05);
}
.mpc-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 20px;
}
.mpc-input-group {
margin-bottom: 15px;
}
.mpc-input-group label {
display: block;
margin-bottom: 8px;
font-weight: 600;
color: #333;
font-size: 14px;
}
.mpc-input-group input, .mpc-input-group select {
width: 100%;
padding: 12px;
border: 1px solid #ccc;
border-radius: 6px;
font-size: 16px;
box-sizing: border-box;
transition: border-color 0.3s;
}
.mpc-input-group input:focus {
border-color: #0073aa;
outline: none;
}
.mpc-btn {
grid-column: span 2;
background-color: #0073aa;
color: white;
border: none;
padding: 15px;
font-size: 18px;
font-weight: bold;
border-radius: 6px;
cursor: pointer;
width: 100%;
margin-top: 10px;
transition: background-color 0.2s;
}
.mpc-btn:hover {
background-color: #005177;
}
.mpc-results {
grid-column: span 2;
background-color: #f8f9fa;
padding: 20px;
border-radius: 8px;
margin-top: 20px;
border-left: 5px solid #0073aa;
display: none;
}
.mpc-result-row {
display: flex;
justify-content: space-between;
margin-bottom: 10px;
font-size: 15px;
color: #555;
padding-bottom: 5px;
border-bottom: 1px dashed #ddd;
}
.mpc-total {
display: flex;
justify-content: space-between;
margin-top: 15px;
font-size: 22px;
font-weight: 800;
color: #2c3e50;
padding-top: 10px;
border-top: 2px solid #ccc;
}
.mpc-article {
max-width: 800px;
margin: 40px auto;
line-height: 1.6;
color: #333;
font-family: inherit;
}
.mpc-article h2 {
color: #2c3e50;
margin-top: 30px;
border-bottom: 2px solid #0073aa;
padding-bottom: 10px;
display: inline-block;
}
.mpc-article p {
margin-bottom: 15px;
font-size: 16px;
}
.mpc-article ul {
margin-bottom: 20px;
padding-left: 20px;
}
.mpc-article li {
margin-bottom: 10px;
}
@media (max-width: 600px) {
.mpc-grid {
grid-template-columns: 1fr;
}
.mpc-btn, .mpc-results {
grid-column: span 1;
}
}
function calculateMortgage() {
// Get Inputs
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 homeInsurance = parseFloat(document.getElementById('homeInsurance').value);
var pmiRate = parseFloat(document.getElementById('pmiRate').value);
var hoaFees = parseFloat(document.getElementById('hoaFees').value);
// Validation
if (isNaN(homePrice) || isNaN(downPayment) || isNaN(interestRate) || isNaN(loanTerm)) {
alert("Please fill in the valid numbers for Home Price, Down Payment, Interest Rate, and Term.");
return;
}
// Handle optional fields as 0 if empty/NaN
if (isNaN(propertyTax)) propertyTax = 0;
if (isNaN(homeInsurance)) homeInsurance = 0;
if (isNaN(pmiRate)) pmiRate = 0;
if (isNaN(hoaFees)) hoaFees = 0;
// Core Calculations
var loanAmount = homePrice – downPayment;
if (loanAmount <= 0) {
alert("Down payment cannot be greater than or equal to the home price.");
return;
}
var monthlyRate = (interestRate / 100) / 12;
var numberOfPayments = loanTerm * 12;
var monthlyPrincipalInterest = 0;
// Mortgage Formula: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1]
if (interestRate === 0) {
monthlyPrincipalInterest = loanAmount / numberOfPayments;
} else {
monthlyPrincipalInterest = loanAmount *
(monthlyRate * Math.pow(1 + monthlyRate, numberOfPayments)) /
(Math.pow(1 + monthlyRate, numberOfPayments) – 1);
}
// Monthly Components
var monthlyTax = propertyTax / 12;
var monthlyInsurance = homeInsurance / 12;
// PMI Calculation: Only applies if Down Payment is less than 20%
var monthlyPMI = 0;
var downPaymentPercentage = (downPayment / homePrice) * 100;
// Even if user enters a PMI rate, we strictly check if DP 0) {
monthlyPMI = (loanAmount * (pmiRate / 100)) / 12;
}
var totalMonthlyPayment = monthlyPrincipalInterest + monthlyTax + monthlyInsurance + monthlyPMI + hoaFees;
// Display Results
document.getElementById('resPI').innerText = '$' + monthlyPrincipalInterest.toFixed(2).replace(/\d(?=(\d{3})+\.)/g, '$&,');
document.getElementById('resTax').innerText = '$' + monthlyTax.toFixed(2).replace(/\d(?=(\d{3})+\.)/g, '$&,');
document.getElementById('resIns').innerText = '$' + monthlyInsurance.toFixed(2).replace(/\d(?=(\d{3})+\.)/g, '$&,');
document.getElementById('resPMI').innerText = '$' + monthlyPMI.toFixed(2).replace(/\d(?=(\d{3})+\.)/g, '$&,');
document.getElementById('resHOA').innerText = '$' + hoaFees.toFixed(2).replace(/\d(?=(\d{3})+\.)/g, '$&,');
document.getElementById('resTotal').innerText = '$' + totalMonthlyPayment.toFixed(2).replace(/\d(?=(\d{3})+\.)/g, '$&,');
// Show Result Div
document.getElementById('mpcResults').style.display = 'block';
}
Understanding Your Monthly Mortgage Payment
Calculating your potential monthly mortgage payment is the first critical step in the home buying process. This tool goes beyond simple principal and interest calculations to give you a realistic view of your housing costs by including property taxes, homeowners insurance, HOA fees, and Private Mortgage Insurance (PMI).
The PITI Formula
Lenders often refer to your total payment as PITI, which stands for:
- Principal: The portion of your payment that pays down the loan balance.
- Interest: The cost of borrowing money from the lender.
- Taxes: Property taxes assessed by your local government, typically held in escrow.
- Insurance: Homeowners insurance to protect against fire, theft, and liabilities.
How PMI Affects Your Payment
Private Mortgage Insurance (PMI) is usually required if your down payment is less than 20% of the home's purchase price. It protects the lender in case of default. PMI rates typically range from 0.5% to 1.5% of the loan amount annually. This calculator allows you to input a custom PMI rate to see exactly how it impacts your monthly budget.
Why Include HOA Fees?
If you are buying a condo, townhouse, or a home in a planned community, you will likely pay Homeowners Association (HOA) fees. These fees are separate from your mortgage but are counted by lenders when calculating your debt-to-income ratio. Always include them in your calculation to ensure you don't overextend your budget.
How to Lower Your Monthly Payment
If the estimated payment is higher than your budget allows, consider these strategies:
- Increase your down payment: This lowers the principal loan amount and may eliminate PMI.
- Shop for a lower interest rate: Even a 0.5% difference can save hundreds of dollars a month.
- Extend the loan term: Moving from a 15-year to a 30-year term reduces monthly payments, though you will pay more interest over time.
- Challenge property tax assessments: Ensure the assessed value of the property aligns with current market conditions.