.calc-container {
max-width: 800px;
margin: 40px auto;
padding: 30px;
background: #ffffff;
border-radius: 12px;
box-shadow: 0 4px 20px rgba(0,0,0,0.08);
font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
border: 1px solid #e0e0e0;
}
.calc-header {
text-align: center;
margin-bottom: 30px;
border-bottom: 2px solid #f0f0f0;
padding-bottom: 20px;
}
.calc-header h2 {
color: #2c3e50;
margin: 0;
font-size: 28px;
}
.calc-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 25px;
}
.form-group {
margin-bottom: 15px;
}
.form-group label {
display: block;
font-weight: 600;
margin-bottom: 8px;
color: #4a5568;
font-size: 14px;
}
.input-wrapper {
position: relative;
display: flex;
align-items: center;
}
.input-prefix, .input-suffix {
position: absolute;
color: #718096;
font-weight: 500;
}
.input-prefix { left: 12px; }
.input-suffix { right: 12px; }
.form-control {
width: 100%;
padding: 12px 12px 12px 25px;
border: 2px solid #e2e8f0;
border-radius: 8px;
font-size: 16px;
transition: border-color 0.2s;
box-sizing: border-box;
}
.form-control.has-suffix {
padding-right: 35px;
padding-left: 12px;
}
.form-control:focus {
border-color: #3182ce;
outline: none;
}
.calc-btn {
grid-column: span 2;
background: #3182ce;
color: white;
border: none;
padding: 15px;
font-size: 18px;
font-weight: bold;
border-radius: 8px;
cursor: pointer;
transition: background 0.2s;
margin-top: 10px;
}
.calc-btn:hover {
background: #2c5282;
}
.results-box {
margin-top: 30px;
padding: 25px;
background: #f7fafc;
border-radius: 10px;
border: 1px solid #cbd5e0;
display: none;
}
.results-header {
text-align: center;
color: #2d3748;
margin-bottom: 20px;
font-size: 18px;
font-weight: 600;
}
.result-row {
display: flex;
justify-content: space-between;
margin-bottom: 12px;
padding-bottom: 12px;
border-bottom: 1px solid #e2e8f0;
}
.result-row:last-child {
border-bottom: none;
margin-bottom: 0;
}
.result-label {
color: #718096;
}
.result-value {
font-weight: bold;
color: #2d3748;
}
.highlight-result {
font-size: 24px;
color: #3182ce;
}
.error-msg {
color: #e53e3e;
text-align: center;
margin-top: 10px;
display: none;
}
.seo-content {
max-width: 800px;
margin: 50px auto;
font-family: 'Segoe UI', Roboto, sans-serif;
line-height: 1.6;
color: #333;
}
.seo-content h2 {
color: #2c3e50;
margin-top: 30px;
}
.seo-content h3 {
color: #34495e;
margin-top: 20px;
}
.seo-content p {
margin-bottom: 15px;
}
.seo-content ul {
margin-bottom: 20px;
}
@media (max-width: 600px) {
.calc-grid {
grid-template-columns: 1fr;
}
.calc-btn {
grid-column: span 1;
}
}
Please enter valid numeric values for Home Price, Rate, and Term.
Principal & Interest:
$0.00
Property Tax (Monthly):
$0.00
Home Insurance (Monthly):
$0.00
Total Monthly Payment:
$0.00
Total Interest Paid Over Loan:
$0.00
Understanding Your Mortgage Calculation
Using a reliable Mortgage Payment Calculator is an essential step in the home buying process. It helps prospective homeowners understand exactly how much they can afford by breaking down the monthly financial commitment associated with a home loan.
How is the Monthly Payment Calculated?
The core of a mortgage payment consists of the Principal and Interest (often abbreviated as P&I). This is calculated using the standard amortization formula:
- Principal: The money you borrowed to buy the house (Home Price minus Down Payment).
- Interest: The cost of borrowing that money, determined by your Annual Percentage Rate (APR).
In addition to P&I, most homeowners must also pay for Property Taxes and Homeowners Insurance. These are often collected by the lender into an escrow account and paid on your behalf. Our calculator allows you to include these optional costs to get a true picture of your "Out-the-Door" monthly obligation.
The Impact of Loan Term and Interest Rate
Two major factors influence your monthly payment: the Loan Term and the Interest Rate.
- Loan Term: A standard 30-year fixed mortgage will have lower monthly payments than a 15-year mortgage, but you will pay significantly more in total interest over the life of the loan.
- Interest Rate: Even a small difference in percentage points (e.g., 6.0% vs 6.5%) can add up to tens of thousands of dollars over 30 years. A higher down payment can sometimes help you secure a lower interest rate.
Why Use This Calculator?
This tool is designed to provide a comprehensive view of your housing costs. By adjusting the "Down Payment" and "Interest Rate" fields, you can simulate different scenarios to find a mortgage plan that fits your budget comfortably. Remember to factor in maintenance costs and utilities, which are separate from your mortgage payment.
function calculateMortgage() {
// 1. Get input elements
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 errorDiv = document.getElementById("errorMsg");
var resultBox = document.getElementById("resultBox");
// 2. Parse values
var price = parseFloat(priceInput.value);
var down = parseFloat(downInput.value) || 0;
var rate = parseFloat(rateInput.value);
var years = parseFloat(termInput.value);
var taxYearly = parseFloat(taxInput.value) || 0;
var insYearly = parseFloat(insInput.value) || 0;
// 3. Validation
if (isNaN(price) || isNaN(rate) || isNaN(years) || price <= 0 || years = price
if (principal <= 0) {
principal = 0;
}
var monthlyRate = rate / 100 / 12;
var numberOfPayments = years * 12;
var monthlyPI = 0;
// Amortization Formula: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1]
if (monthlyRate === 0) {
monthlyPI = principal / numberOfPayments;
} else {
monthlyPI = principal * (monthlyRate * Math.pow(1 + monthlyRate, numberOfPayments)) / (Math.pow(1 + monthlyRate, numberOfPayments) – 1);
}
if (isNaN(monthlyPI) || !isFinite(monthlyPI)) {
monthlyPI = 0;
}
var monthlyTax = taxYearly / 12;
var monthlyIns = insYearly / 12;
var totalMonthly = monthlyPI + monthlyTax + monthlyIns;
var totalInterest = (monthlyPI * numberOfPayments) – principal;
// Handle negative interest edge case (if something weird happens, though principal logic covers it)
if (totalInterest < 0) totalInterest = 0;
// 5. Display Results
document.getElementById("resPI").innerHTML = "$" + monthlyPI.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("resTax").innerHTML = "$" + monthlyTax.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("resIns").innerHTML = "$" + monthlyIns.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("resTotal").innerHTML = "$" + totalMonthly.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("resTotalInterest").innerHTML = "$" + totalInterest.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
}