#mortgage-calculator-plugin {
font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
max-width: 800px;
margin: 0 auto;
color: #333;
line-height: 1.6;
}
.calc-container {
background: #ffffff;
padding: 30px;
border-radius: 8px;
box-shadow: 0 4px 15px rgba(0,0,0,0.1);
margin-bottom: 40px;
border: 1px solid #e0e0e0;
}
.calc-header {
text-align: center;
margin-bottom: 25px;
color: #2c3e50;
}
.input-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 20px;
}
@media (max-width: 600px) {
.input-grid {
grid-template-columns: 1fr;
}
}
.input-group {
margin-bottom: 15px;
}
.input-group label {
display: block;
margin-bottom: 5px;
font-weight: 600;
font-size: 0.9em;
color: #555;
}
.input-group input {
width: 100%;
padding: 10px;
border: 1px solid #ddd;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
}
.input-group input:focus {
border-color: #3498db;
outline: none;
box-shadow: 0 0 5px rgba(52,152,219,0.3);
}
.calc-btn {
width: 100%;
padding: 15px;
background-color: #2980b9;
color: white;
border: none;
border-radius: 4px;
font-size: 18px;
font-weight: bold;
cursor: pointer;
transition: background-color 0.3s;
margin-top: 10px;
}
.calc-btn:hover {
background-color: #2471a3;
}
.results-section {
margin-top: 30px;
padding: 20px;
background-color: #f8f9fa;
border-radius: 6px;
border-left: 5px solid #2980b9;
display: none;
}
.result-row {
display: flex;
justify-content: space-between;
margin-bottom: 10px;
padding-bottom: 10px;
border-bottom: 1px solid #eee;
}
.result-row:last-child {
border-bottom: none;
margin-bottom: 0;
padding-bottom: 0;
}
.result-label {
font-weight: 500;
}
.result-value {
font-weight: 700;
color: #2c3e50;
}
.main-result {
font-size: 1.4em;
color: #27ae60;
}
.seo-content {
margin-top: 40px;
padding: 20px;
background: #fff;
}
.seo-content h2 {
color: #2c3e50;
margin-top: 30px;
font-size: 1.5em;
}
.seo-content h3 {
color: #34495e;
margin-top: 20px;
font-size: 1.2em;
}
.seo-content p {
margin-bottom: 15px;
color: #555;
}
.seo-content ul {
margin-bottom: 15px;
padding-left: 20px;
}
.seo-content li {
margin-bottom: 8px;
}
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 loanTerm = parseFloat(document.getElementById("loanTerm").value);
var propertyTax = parseFloat(document.getElementById("propertyTax").value);
var insurance = parseFloat(document.getElementById("insurance").value);
var hoa = parseFloat(document.getElementById("hoa").value);
// Validation
if (isNaN(homePrice) || isNaN(downPayment) || isNaN(interestRate) || isNaN(loanTerm)) {
alert("Please enter valid numbers for Home Price, Down Payment, Interest Rate, and Loan Term.");
return;
}
if (homePrice <= 0 || loanTerm <= 0) {
alert("Home Price and Loan Term must be greater than zero.");
return;
}
// Defaults for optional fields if empty
if (isNaN(propertyTax)) propertyTax = 0;
if (isNaN(insurance)) insurance = 0;
if (isNaN(hoa)) hoa = 0;
// Core Calculations
var principal = homePrice – downPayment;
if (principal <= 0) {
alert("Down payment cannot equal or exceed Home Price for a mortgage calculation.");
return;
}
var monthlyRate = (interestRate / 100) / 12;
var numberOfPayments = loanTerm * 12;
var monthlyPI = 0;
// Handle zero interest rate edge case
if (interestRate === 0) {
monthlyPI = principal / numberOfPayments;
} else {
// Formula: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
monthlyPI = (principal * monthlyRate * Math.pow(1 + monthlyRate, numberOfPayments)) / (Math.pow(1 + monthlyRate, numberOfPayments) – 1);
}
var monthlyTax = propertyTax / 12;
var monthlyInsurance = insurance / 12;
var totalMonthlyPayment = monthlyPI + monthlyTax + monthlyInsurance + hoa;
var totalCostOfLoan = (monthlyPI * numberOfPayments);
var totalInterest = totalCostOfLoan – principal;
// Output Formatting
var formatter = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
minimumFractionDigits: 2
});
// Update DOM
document.getElementById("res-pi").innerHTML = formatter.format(monthlyPI);
document.getElementById("res-tax").innerHTML = formatter.format(monthlyTax);
document.getElementById("res-ins").innerHTML = formatter.format(monthlyInsurance);
document.getElementById("res-hoa").innerHTML = formatter.format(hoa);
document.getElementById("res-total").innerHTML = formatter.format(totalMonthlyPayment);
document.getElementById("res-total-interest").innerHTML = formatter.format(totalInterest);
// Show Results
document.getElementById("results").style.display = "block";
}
Monthly Mortgage Calculator
Principal & Interest:
Property Tax (Monthly):
Home Insurance (Monthly):
HOA Fees (Monthly):
Total Monthly Payment:
Total Interest Paid over Loan:
Understanding Your Monthly Mortgage Payment
Calculating your monthly mortgage payment is the first critical step in the home-buying process. While the sticker price of a home gives you a general idea of cost, your actual monthly obligation involves several components known collectively as PITI: Principal, Interest, Taxes, and Insurance.
Breakdown of Mortgage Costs
- Principal & Interest (P&I): This is the core of your loan. The principal repays the amount you borrowed, while the interest is the cost of borrowing that money. Early in your loan term, a higher percentage of your payment goes toward interest.
- Property Taxes: Local governments assess taxes on real estate to fund public services. These are often collected by your lender in an escrow account and paid annually on your behalf.
- Homeowners Insurance: Lenders require insurance to protect the asset against fire, theft, and other damages. Like taxes, this is usually bundled into your monthly payment.
- HOA Fees: If you buy a condo or a home in a planned community, you may owe Homeowners Association dues. While often paid directly to the association, including them in this calculator gives you a true picture of your housing expenses.
How Interest Rates Impact Your Buying Power
Even a small fluctuation in interest rates can significantly affect 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 hundreds of dollars and your total interest paid over 30 years by tens of thousands. Use the calculator above to scenario-test different rates to see what you can comfortably afford.
Fixed-Rate vs. Adjustable-Rate Mortgages
This calculator assumes a Fixed-Rate Mortgage, where the interest rate remains constant for the life of the loan (typically 15 or 30 years). This offers stability and predictability. Adjustable-Rate Mortgages (ARMs) may start with a lower rate that changes after a set period, potentially increasing your future payments.
Strategies to Lower Your Monthly Payment
If the estimated payment is higher than your budget allows, consider these strategies:
- Increase Your Down Payment: Putting more money down reduces the principal loan amount and may eliminate the need for Private Mortgage Insurance (PMI).
- Extend the Loan Term: Opting for a 30-year term instead of a 15-year term lowers monthly payments, though you will pay more in total interest over time.
- Shop for Lower Rates: Improve your credit score before applying or shop around with multiple lenders to secure a better interest rate.