.calculator-wrapper {
max-width: 800px;
margin: 0 auto;
font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
line-height: 1.6;
color: #333;
}
.calc-header {
text-align: center;
margin-bottom: 30px;
background: #f4f8fb;
padding: 20px;
border-radius: 8px;
border-left: 5px solid #2c3e50;
}
.calc-container {
background: #ffffff;
padding: 30px;
border-radius: 8px;
box-shadow: 0 4px 15px rgba(0,0,0,0.1);
border: 1px solid #e1e1e1;
}
.input-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 20px;
}
.input-group {
margin-bottom: 15px;
}
.input-group label {
display: block;
margin-bottom: 8px;
font-weight: 600;
font-size: 14px;
color: #2c3e50;
}
.input-group input, .input-group select {
width: 100%;
padding: 12px;
border: 1px solid #ddd;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box; /* Ensures padding doesn't affect width */
}
.input-group input:focus {
border-color: #3498db;
outline: none;
box-shadow: 0 0 5px rgba(52,152,219,0.3);
}
.full-width {
grid-column: span 2;
}
.calc-btn {
background-color: #27ae60;
color: white;
border: none;
padding: 15px 30px;
font-size: 18px;
font-weight: bold;
border-radius: 4px;
cursor: pointer;
width: 100%;
margin-top: 20px;
transition: background-color 0.3s;
}
.calc-btn:hover {
background-color: #219150;
}
.results-section {
margin-top: 30px;
padding-top: 20px;
border-top: 2px solid #f0f0f0;
display: none;
}
.result-box {
background: #f8f9fa;
padding: 20px;
border-radius: 6px;
text-align: center;
margin-bottom: 20px;
}
.result-main {
font-size: 36px;
color: #2c3e50;
font-weight: 800;
margin: 10px 0;
}
.breakdown-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 15px;
}
.breakdown-item {
background: #fff;
padding: 15px;
border: 1px solid #eee;
border-radius: 4px;
}
.breakdown-label {
font-size: 13px;
color: #7f8c8d;
text-transform: uppercase;
letter-spacing: 1px;
}
.breakdown-value {
font-size: 18px;
font-weight: 600;
color: #34495e;
}
.seo-content {
margin-top: 50px;
}
.seo-content h2 {
color: #2c3e50;
border-bottom: 2px solid #ecf0f1;
padding-bottom: 10px;
margin-top: 40px;
}
.seo-content p {
margin-bottom: 15px;
}
@media (max-width: 600px) {
.input-grid, .breakdown-grid {
grid-template-columns: 1fr;
}
.full-width {
grid-column: span 1;
}
}
function calculateMortgage() {
// 1. 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 loanTermYears = parseInt(document.getElementById("loanTerm").value);
var propertyTaxYearly = parseFloat(document.getElementById("propertyTax").value);
var homeInsuranceYearly = parseFloat(document.getElementById("homeInsurance").value);
var hoaFeesMonthly = parseFloat(document.getElementById("hoaFees").value);
// 2. Validation
if (isNaN(homePrice) || isNaN(downPayment) || isNaN(interestRate) || isNaN(loanTermYears)) {
alert("Please enter valid numbers for the required fields.");
return;
}
// 3. Setup Variables for Calculation
var principal = homePrice – downPayment;
var monthlyInterestRate = (interestRate / 100) / 12;
var numberOfPayments = loanTermYears * 12;
// Handle edge case where principal is 0 or negative
if (principal <= 0) {
alert("Down payment cannot be greater than or equal to Home Price.");
return;
}
// 4. Calculate Principal & Interest (P&I)
// Formula: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
var monthlyPrincipalAndInterest = 0;
if (interestRate === 0) {
monthlyPrincipalAndInterest = principal / numberOfPayments;
} else {
monthlyPrincipalAndInterest = principal *
(monthlyInterestRate * Math.pow(1 + monthlyInterestRate, numberOfPayments)) /
(Math.pow(1 + monthlyInterestRate, numberOfPayments) – 1);
}
// 5. Calculate Escrow items (Tax, Insurance)
var monthlyTax = isNaN(propertyTaxYearly) ? 0 : propertyTaxYearly / 12;
var monthlyInsurance = isNaN(homeInsuranceYearly) ? 0 : homeInsuranceYearly / 12;
var monthlyHOA = isNaN(hoaFeesMonthly) ? 0 : hoaFeesMonthly;
// 6. Calculate Totals
var totalMonthlyPayment = monthlyPrincipalAndInterest + monthlyTax + monthlyInsurance + monthlyHOA;
var totalCostOfLoan = (monthlyPrincipalAndInterest * numberOfPayments);
var totalInterestPaid = totalCostOfLoan – principal;
// 7. Display Results
// Helper for currency formatting
var formatter = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
});
document.getElementById("totalMonthlyPayment").innerHTML = formatter.format(totalMonthlyPayment);
document.getElementById("principalInterest").innerHTML = formatter.format(monthlyPrincipalAndInterest);
document.getElementById("monthlyTax").innerHTML = formatter.format(monthlyTax);
document.getElementById("monthlyInsurance").innerHTML = formatter.format(monthlyInsurance);
document.getElementById("totalInterest").innerHTML = formatter.format(totalInterestPaid);
// Show the results section
document.getElementById("resultsArea").style.display = "block";
}
Mortgage Payment Calculator
Calculate your estimated monthly payments, including Principal, Interest, Taxes, and Insurance (PITI).
Understanding Your Mortgage Calculation
Purchasing a home is likely the largest financial decision you will make in your lifetime. Understanding exactly how your monthly payments are calculated is crucial for financial planning. Unlike simple loan calculators, a true mortgage calculation involves several components often referred to as PITI: Principal, Interest, Taxes, and Insurance.
This calculator breaks down the total cost of homeownership, helping you avoid "payment shock" by accounting for hidden costs like property taxes, homeowner's insurance, and Private Mortgage Insurance (PMI).
30 Years
20 Years
15 Years
10 Years
Estimated Total Monthly Payment
$0.00
Includes Taxes, Insurance & Fees
Principal & Interest
$0.00
Monthly Tax Paid
$0.00
Monthly Insurance
$0.00
Total Interest Cost
$0.00
How Mortgage Amortization Works
The core of your mortgage payment is determined by an amortization formula. In the early years of a 30-year fixed mortgage, the majority of your payment goes toward interest, while a smaller portion reduces your principal balance. As time passes, this ratio flips.
Key Factors Affecting Your Payment
- Interest Rate: Even a 0.5% difference in rate can save or cost you tens of thousands of dollars over the life of the loan.
- Loan Term: A 15-year term will have higher monthly payments than a 30-year term, but you will pay significantly less total interest.
- Property Taxes: These are assessed by your local government and are often bundled into your monthly mortgage payment via an escrow account.
When is PMI Required?
If your down payment is less than 20% of the home price, lenders typically require Private Mortgage Insurance (PMI). This protects the lender if you default. You can include this estimated cost in the "Monthly HOA / PMI" field above to get a more accurate monthly figure.