.calc-container {
max-width: 800px;
margin: 20px auto;
background: #ffffff;
border: 1px solid #e0e0e0;
border-radius: 8px;
box-shadow: 0 4px 12px rgba(0,0,0,0.05);
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
color: #333;
}
.calc-header {
background: #2c3e50;
color: #fff;
padding: 20px;
border-radius: 8px 8px 0 0;
text-align: center;
}
.calc-header h3 {
margin: 0;
font-size: 24px;
font-weight: 600;
}
.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 #eee;
display: flex;
flex-direction: column;
justify-content: center;
}
.form-group {
margin-bottom: 20px;
}
.form-group label {
display: block;
margin-bottom: 8px;
font-weight: 600;
font-size: 14px;
color: #555;
}
.input-wrapper {
position: relative;
display: flex;
align-items: center;
}
.input-prefix, .input-suffix {
padding: 10px 15px;
background: #e9ecef;
border: 1px solid #ced4da;
color: #495057;
font-weight: 500;
}
.input-prefix {
border-right: none;
border-radius: 4px 0 0 4px;
}
.input-suffix {
border-left: none;
border-radius: 0 4px 4px 0;
}
.calc-input {
width: 100%;
padding: 10px;
border: 1px solid #ced4da;
font-size: 16px;
border-radius: 0;
outline: none;
}
.calc-input:focus {
border-color: #3498db;
box-shadow: 0 0 0 2px rgba(52,152,219,0.2);
}
.input-rounded-left {
border-radius: 4px 0 0 4px;
}
.input-rounded-right {
border-radius: 0 4px 4px 0;
}
.input-rounded-full {
border-radius: 4px;
}
.calc-btn {
width: 100%;
padding: 14px;
background: #27ae60;
color: white;
border: none;
border-radius: 4px;
font-size: 18px;
font-weight: 600;
cursor: pointer;
transition: background 0.2s;
margin-top: 10px;
}
.calc-btn:hover {
background: #219150;
}
.result-item {
margin-bottom: 20px;
text-align: center;
border-bottom: 1px solid #ddd;
padding-bottom: 15px;
}
.result-item:last-child {
border-bottom: none;
margin-bottom: 0;
padding-bottom: 0;
}
.result-label {
font-size: 14px;
color: #777;
margin-bottom: 5px;
text-transform: uppercase;
letter-spacing: 0.5px;
}
.result-value {
font-size: 32px;
font-weight: 700;
color: #2c3e50;
}
.result-value-sm {
font-size: 24px;
color: #555;
}
.error-msg {
color: #e74c3c;
font-size: 14px;
text-align: center;
margin-top: 10px;
display: none;
}
.article-content {
max-width: 800px;
margin: 40px auto;
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
line-height: 1.6;
color: #333;
}
.article-content h2 {
font-size: 28px;
color: #2c3e50;
margin-top: 40px;
border-bottom: 2px solid #eee;
padding-bottom: 10px;
}
.article-content h3 {
font-size: 22px;
color: #2c3e50;
margin-top: 30px;
}
.article-content p {
margin-bottom: 15px;
font-size: 17px;
}
.article-content ul {
margin-bottom: 20px;
padding-left: 20px;
}
.article-content li {
margin-bottom: 10px;
font-size: 17px;
}
@media (max-width: 600px) {
.calc-body {
flex-direction: column;
}
}
Total Monthly Payment
$0.00
Principal & Interest
$0.00
Total Interest Paid
$0.00
Understanding Your Mortgage Calculation
Purchasing a home is one of the most significant financial decisions you will make in your lifetime. Our Mortgage Payment Calculator helps you estimate your monthly financial commitment, ensuring you can budget effectively for your new property. By understanding how variables like interest rates, loan terms, and down payments affect your bottom line, you can make smarter home-buying choices.
How is the Monthly Payment Calculated?
A typical mortgage payment consists of four main components, often referred to as PITI:
- Principal: The portion of your payment that pays down the loan balance.
- Interest: The cost of borrowing money from your lender.
- Taxes: Property taxes charged by your local government, usually held in escrow.
- Insurance: Homeowners insurance to protect your property against damage.
Our calculator combines these elements to give you a realistic "Total Monthly Payment" figure.
The Impact of Interest Rates
The interest rate is arguably the most critical factor in determining your monthly payment and the total cost of the loan. Even a small difference of 0.5% can save—or cost—you tens of thousands of dollars over the life of a 30-year loan. For example, on a $300,000 loan, a rate increase from 6% to 7% increases the monthly payment significantly and adds roughly $70,000 in total interest paid over 30 years.
Loan Term: 15 Years vs. 30 Years
Choosing between a 15-year and a 30-year mortgage involves a trade-off between monthly affordability and long-term savings.
30-Year Term: Offers lower monthly payments, making the home more affordable day-to-day, but you will pay significantly more in interest over the life of the loan.
15-Year Term: Comes with higher monthly payments, but you build equity much faster and usually secure a lower interest rate, resulting in massive interest savings.
Why the Down Payment Matters
Your down payment reduces the principal loan amount immediately. A larger down payment (typically 20% or more) can help you avoid Private Mortgage Insurance (PMI), lower your monthly installments, and provide an instant equity buffer in your home. If you put down less than 20%, lenders often view the loan as riskier, which may result in a higher interest rate.
function calculateMortgage() {
var homePrice = document.getElementById('homePrice').value;
var downPayment = document.getElementById('downPayment').value;
var interestRate = document.getElementById('interestRate').value;
var loanTerm = document.getElementById('loanTerm').value;
var propertyTax = document.getElementById('propertyTax').value;
var homeInsurance = document.getElementById('homeInsurance').value;
var errorMsg = document.getElementById('errorMsg');
// Reset error
errorMsg.style.display = 'none';
// Validation
if (homePrice === " || downPayment === " || interestRate === " || loanTerm === " || propertyTax === " || homeInsurance === ") {
errorMsg.innerText = "Please fill in all fields.";
errorMsg.style.display = 'block';
return;
}
// Convert to numbers
var price = parseFloat(homePrice);
var down = parseFloat(downPayment);
var rate = parseFloat(interestRate);
var term = parseFloat(loanTerm);
var tax = parseFloat(propertyTax);
var insurance = parseFloat(homeInsurance);
if (isNaN(price) || isNaN(down) || isNaN(rate) || isNaN(term) || isNaN(tax) || isNaN(insurance)) {
errorMsg.innerText = "Please enter valid numeric values.";
errorMsg.style.display = 'block';
return;
}
if (price <= 0 || term <= 0) {
errorMsg.innerText = "Price and Term must be greater than zero.";
errorMsg.style.display = 'block';
return;
}
// Calculations
var principal = price – down;
// Handle edge case where principal is 0 or negative
if (principal < 0) {
errorMsg.innerText = "Down payment cannot be larger than Home Price.";
errorMsg.style.display = 'block';
return;
}
var monthlyRate = (rate / 100) / 12;
var numberOfPayments = term * 12;
var monthlyPI = 0;
// Standard Amortization Formula
if (rate === 0) {
monthlyPI = principal / numberOfPayments;
} else {
monthlyPI = principal * (monthlyRate * Math.pow(1 + monthlyRate, numberOfPayments)) / (Math.pow(1 + monthlyRate, numberOfPayments) – 1);
}
var monthlyTax = tax / 12;
var monthlyInsurance = insurance / 12;
var totalMonthlyPayment = monthlyPI + monthlyTax + monthlyInsurance;
var totalAmountPaid = (monthlyPI * numberOfPayments);
var totalInterest = totalAmountPaid – principal;
var totalCostOfLoan = totalAmountPaid + (tax * term) + (insurance * term);
// Update DOM
document.getElementById('monthlyPayment').innerText = formatCurrency(totalMonthlyPayment);
document.getElementById('piPayment').innerText = formatCurrency(monthlyPI);
document.getElementById('totalInterest').innerText = formatCurrency(totalInterest);
document.getElementById('totalCost').innerText = formatCurrency(totalCostOfLoan);
}
function formatCurrency(num) {
return new Intl.NumberFormat('en-US', { style: 'currency', currency: 'USD' }).format(num);
}
// Initial calculation on load for demo purposes
calculateMortgage();