.calc-container {
max-width: 800px;
margin: 20px auto;
font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
background: #ffffff;
border: 1px solid #e0e0e0;
border-radius: 8px;
box-shadow: 0 4px 12px rgba(0,0,0,0.05);
overflow: hidden;
}
.calc-header {
background: #2c3e50;
color: white;
padding: 20px;
text-align: center;
}
.calc-header h2 {
margin: 0;
font-size: 24px;
}
.calc-body {
padding: 30px;
display: flex;
flex-wrap: wrap;
gap: 30px;
}
.calc-inputs {
flex: 1;
min-width: 300px;
}
.calc-results {
flex: 1;
min-width: 300px;
background: #f8f9fa;
padding: 20px;
border-radius: 8px;
border: 1px solid #e9ecef;
display: flex;
flex-direction: column;
justify-content: center;
}
.form-group {
margin-bottom: 15px;
}
.form-group label {
display: block;
margin-bottom: 5px;
font-weight: 600;
color: #333;
font-size: 14px;
}
.input-wrapper {
position: relative;
}
.input-wrapper input {
width: 100%;
padding: 10px 10px 10px 35px; /* space for symbol */
border: 1px solid #ced4da;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
}
.input-wrapper .symbol {
position: absolute;
left: 10px;
top: 50%;
transform: translateY(-50%);
color: #6c757d;
}
.calc-btn {
width: 100%;
padding: 12px;
background: #27ae60;
color: white;
border: none;
border-radius: 4px;
font-size: 16px;
font-weight: bold;
cursor: pointer;
transition: background 0.3s;
margin-top: 10px;
}
.calc-btn:hover {
background: #219150;
}
.result-row {
display: flex;
justify-content: space-between;
margin-bottom: 12px;
font-size: 15px;
color: #555;
padding-bottom: 8px;
border-bottom: 1px solid #e0e0e0;
}
.result-row.total {
border-bottom: none;
margin-top: 15px;
font-weight: 800;
color: #2c3e50;
font-size: 20px;
align-items: center;
}
.result-value {
font-weight: 700;
}
.calc-article {
max-width: 800px;
margin: 40px auto;
padding: 0 20px;
color: #333;
line-height: 1.6;
}
.calc-article h2 {
color: #2c3e50;
margin-top: 30px;
border-bottom: 2px solid #27ae60;
padding-bottom: 10px;
display: inline-block;
}
.calc-article p {
margin-bottom: 15px;
}
.calc-article ul {
margin-bottom: 15px;
padding-left: 20px;
}
.calc-article li {
margin-bottom: 8px;
}
@media (max-width: 768px) {
.calc-body {
flex-direction: column;
}
}
Principal & Interest:
$0.00
Monthly Tax:
$0.00
Monthly Insurance:
$0.00
Monthly HOA:
$0.00
Total Monthly (PITI):
$0.00
Loan Amount:
$0.00
Total Interest Paid:
$0.00
function calculateMortgage() {
// 1. Get DOM elements and values
var priceInput = document.getElementById("homePrice");
var downInput = document.getElementById("downPayment");
var rateInput = document.getElementById("interestRate");
var termInput = document.getElementById("loanTerm");
var taxInput = document.getElementById("propertyTax");
var insInput = document.getElementById("homeInsurance");
var hoaInput = document.getElementById("hoaDues");
var price = parseFloat(priceInput.value);
var down = parseFloat(downInput.value);
var rate = parseFloat(rateInput.value);
var term = parseFloat(termInput.value);
var tax = parseFloat(taxInput.value);
var ins = parseFloat(insInput.value);
var hoa = parseFloat(hoaInput.value);
// 2. Validation
if (isNaN(price) || isNaN(down) || isNaN(rate) || isNaN(term)) {
alert("Please enter valid numbers for Price, Down Payment, Rate, and Term.");
return;
}
// Handle optional fields as 0 if empty/NaN
if (isNaN(tax)) tax = 0;
if (isNaN(ins)) ins = 0;
if (isNaN(hoa)) hoa = 0;
// 3. Calculation Logic
var principal = price – down;
if (principal 0) {
monthlyPI = principal / numberOfPayments;
}
} else {
// Standard Amortization Formula: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
var factor = Math.pow(1 + monthlyRate, numberOfPayments);
monthlyPI = principal * ((monthlyRate * factor) / (factor – 1));
}
var monthlyTax = tax / 12;
var monthlyIns = ins / 12;
var monthlyTotal = monthlyPI + monthlyTax + monthlyIns + hoa;
var totalCost = (monthlyPI * numberOfPayments);
var totalInterest = totalCost – principal;
// 4. Update Result Display
// Helper function for currency formatting
var fmt = new Intl.NumberFormat('en-US', { style: 'currency', currency: 'USD' });
document.getElementById("resPI").innerText = fmt.format(monthlyPI);
document.getElementById("resTax").innerText = fmt.format(monthlyTax);
document.getElementById("resIns").innerText = fmt.format(monthlyIns);
document.getElementById("resHOA").innerText = fmt.format(hoa);
document.getElementById("resTotal").innerText = fmt.format(monthlyTotal);
document.getElementById("resLoanAmount").innerText = fmt.format(principal);
document.getElementById("resTotalInterest").innerText = fmt.format(totalInterest);
}
// Initial calculation on load
calculateMortgage();
Understanding Your Mortgage PITI Payment
When calculating mortgage affordability, many prospective homebuyers only focus on the principal and interest payment. However, the true cost of homeownership is often referred to as PITI: Principal, Interest, Taxes, and Insurance. This calculator provides a comprehensive view of your monthly financial obligation.
The Four Components of PITI
- Principal: The portion of your payment that goes toward paying down the loan balance (the amount you borrowed).
- Interest: The cost of borrowing money, paid to the lender. In the early years of a mortgage, a large percentage of your payment goes toward interest.
- Taxes: Property taxes assessed by your local government. Lenders often collect this monthly and hold it in an escrow account to pay the bill annually on your behalf.
- Insurance: Homeowners insurance protects your property against damage. Like taxes, this is often collected monthly in escrow.
Why This Calculation Matters for SEO and Planning
Understanding your Debt-to-Income (DTI) ratio requires an accurate monthly housing cost figure. If you only calculate Principal and Interest, you might underestimate your monthly budget by hundreds of dollars due to taxes and HOA fees. Lenders use the full PITI figure to determine how much you can borrow.
Tips to Lower Your Monthly Payment
If the result from the calculator is higher than your budget allows, consider these strategies:
- Increase your Down Payment: This lowers the principal loan amount and may eliminate the need for Private Mortgage Insurance (PMI).
- Shop for Lower Insurance Rates: Insurance premiums vary significantly between providers.
- Consider Points: Paying "discount points" upfront can permanently lower your interest rate.
- Look for Low HOA Properties: High Homeowners Association dues can drastically reduce your buying power.
Use this tool to experiment with different home prices, down payments, and interest rates to find a mortgage plan that fits your financial goals.