.mortgage-calc-wrapper {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
max-width: 800px;
margin: 20px auto;
border: 1px solid #e0e0e0;
border-radius: 8px;
box-shadow: 0 4px 12px rgba(0,0,0,0.05);
background: #fff;
padding: 0;
overflow: hidden;
}
.calc-header {
background: #2c3e50;
color: #fff;
padding: 20px;
text-align: center;
}
.calc-header h2 {
margin: 0;
font-size: 24px;
}
.calc-body {
padding: 25px;
display: flex;
flex-wrap: wrap;
gap: 20px;
}
.calc-inputs {
flex: 1;
min-width: 300px;
}
.calc-results-box {
flex: 1;
min-width: 300px;
background: #f8f9fa;
border-radius: 6px;
padding: 20px;
display: flex;
flex-direction: column;
justify-content: center;
}
.input-group {
margin-bottom: 15px;
}
.input-group label {
display: block;
font-weight: 600;
margin-bottom: 5px;
color: #333;
font-size: 14px;
}
.input-wrapper {
position: relative;
}
.input-wrapper input, .input-wrapper select {
width: 100%;
padding: 10px 10px 10px 30px; /* Space for symbol */
border: 1px solid #ccc;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
}
.input-wrapper select {
padding-left: 10px;
}
.symbol {
position: absolute;
left: 10px;
top: 50%;
transform: translateY(-50%);
color: #777;
}
.suffix {
position: absolute;
right: 10px;
top: 50%;
transform: translateY(-50%);
color: #777;
}
.calc-btn {
width: 100%;
padding: 12px;
background: #27ae60;
color: white;
border: none;
border-radius: 4px;
font-size: 18px;
font-weight: bold;
cursor: pointer;
margin-top: 10px;
transition: background 0.3s;
}
.calc-btn:hover {
background: #219150;
}
.result-row {
display: flex;
justify-content: space-between;
margin-bottom: 12px;
font-size: 15px;
color: #555;
border-bottom: 1px dashed #ddd;
padding-bottom: 8px;
}
.result-row.main-total {
font-size: 24px;
font-weight: 800;
color: #2c3e50;
border-bottom: none;
margin-top: 10px;
align-items: center;
}
.error-msg {
color: red;
font-size: 13px;
display: none;
margin-top: 5px;
}
.seo-content {
max-width: 800px;
margin: 40px auto;
line-height: 1.6;
color: #333;
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}
.seo-content h2 {
color: #2c3e50;
border-bottom: 2px solid #27ae60;
padding-bottom: 10px;
margin-top: 30px;
}
.seo-content h3 {
color: #2c3e50;
margin-top: 25px;
}
.seo-content p {
margin-bottom: 15px;
}
.seo-content ul {
margin-bottom: 20px;
}
.seo-content li {
margin-bottom: 8px;
}
@media (max-width: 600px) {
.calc-body {
flex-direction: column;
}
}
Monthly Breakdown
Principal & Interest:
$0.00
Property Tax:
$0.00
Home Insurance:
$0.00
PMI (Est.):
$0.00
Total Payment:
$0.00
Total Loan Amount:
$0.00
Total Interest Paid:
$0.00
function calculateMortgage() {
// 1. Get DOM Elements
var homePriceInput = document.getElementById("mc-home-price");
var downPaymentInput = document.getElementById("mc-down-payment");
var rateInput = document.getElementById("mc-interest-rate");
var termInput = document.getElementById("mc-loan-term");
var taxInput = document.getElementById("mc-prop-tax");
var insuranceInput = document.getElementById("mc-insurance");
var errorMsg = document.getElementById("mc-error");
// 2. Parse Values
var homePrice = parseFloat(homePriceInput.value);
var downPayment = parseFloat(downPaymentInput.value);
var annualRate = parseFloat(rateInput.value);
var years = parseInt(termInput.value);
var annualTax = parseFloat(taxInput.value);
var annualIns = parseFloat(insuranceInput.value);
// 3. Validation
if (isNaN(homePrice) || isNaN(downPayment) || isNaN(annualRate) || isNaN(years) ||
homePrice <= 0) {
errorMsg.style.display = "block";
return;
}
errorMsg.style.display = "none";
// Handle optional fields being empty or NaN
if (isNaN(annualTax)) annualTax = 0;
if (isNaN(annualIns)) annualIns = 0;
// 4. Core Calculations
var loanAmount = homePrice – downPayment;
// Handle full cash purchase
if (loanAmount 0) {
var ltv = (loanAmount / homePrice) * 100;
if (ltv > 80) {
// Approximate PMI rate: 0.5% of loan amount annually
pmi = (loanAmount * 0.005) / 12;
}
}
// 7. Total Monthly Payment
var totalMonthly = monthlyPI + monthlyTax + monthlyIns + pmi;
// 8. Update UI
// Helper for formatting currency
var fmt = new Intl.NumberFormat('en-US', { style: 'currency', currency: 'USD' });
document.getElementById("res-pi").innerHTML = fmt.format(monthlyPI);
document.getElementById("res-tax").innerHTML = fmt.format(monthlyTax);
document.getElementById("res-ins").innerHTML = fmt.format(monthlyIns);
document.getElementById("res-pmi").innerHTML = fmt.format(pmi);
document.getElementById("res-total").innerHTML = fmt.format(totalMonthly);
document.getElementById("res-loan-amount").innerHTML = fmt.format(loanAmount);
document.getElementById("res-total-interest").innerHTML = fmt.format(totalInterest);
}
// Run once on load to populate defaults
window.onload = function() {
calculateMortgage();
};
Understanding How Your Mortgage Is Calculated
Using a mortgage calculator is the first step in the home buying journey. It helps you estimate your monthly financial commitment beyond just the asking price of the home. This tool breaks down the four critical components of your monthly payment: Principal, Interest, Taxes, and Insurance (often collectively referred to as PITI).
1. Principal and Interest (P&I)
This is the core of your mortgage payment. Principal is the money that goes towards paying down the actual loan balance. Interest is the cost of borrowing that money from the lender. In the early years of a 30-year fixed mortgage, a large percentage of your payment goes toward interest, while in later years, more goes toward the principal.
2. Property Taxes and Homeowners Insurance (Escrow)
Most lenders require you to pay a portion of your annual property taxes and homeowners insurance every month. These funds are held in an "escrow account" and paid on your behalf when due.
- Property Tax: Determined by your local government based on the assessed value of the property.
- Homeowners Insurance: Protects your home against damage from fire, theft, and liabilities.
3. What is PMI (Private Mortgage Insurance)?
If you put down less than 20% of the home's purchase price, lenders typically view the loan as higher risk and require Private Mortgage Insurance (PMI). This calculator automatically estimates PMI costs if your down payment is below the 20% threshold. Once you build up 20% equity in your home, you can usually request to have PMI removed, lowering your monthly payment.
How to Lower Your Monthly Payment
To reduce your estimated monthly payment, consider increasing your down payment to avoid PMI, shopping around for a lower interest rate, or opting for a longer loan term (though this increases the total interest paid over the life of the loan). Use the calculator above to experiment with these variables to find a monthly budget that works for you.