.mp-calculator-wrapper {
font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
max-width: 800px;
margin: 0 auto;
padding: 20px;
background: #f9f9f9;
border: 1px solid #e0e0e0;
border-radius: 8px;
box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}
.mp-calc-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 20px;
}
.mp-input-group {
margin-bottom: 15px;
}
.mp-input-group label {
display: block;
font-weight: 600;
margin-bottom: 5px;
color: #333;
}
.mp-input-group input, .mp-input-group select {
width: 100%;
padding: 10px;
border: 1px solid #ccc;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
}
.mp-input-group span.suffix {
position: absolute;
right: 10px;
top: 38px;
color: #666;
}
.mp-full-width {
grid-column: span 2;
}
.mp-btn-calculate {
background-color: #2c3e50;
color: white;
border: none;
padding: 15px 30px;
font-size: 18px;
font-weight: bold;
border-radius: 5px;
cursor: pointer;
width: 100%;
transition: background-color 0.3s;
margin-top: 10px;
}
.mp-btn-calculate:hover {
background-color: #34495e;
}
.mp-results-area {
margin-top: 30px;
background: #fff;
padding: 20px;
border-radius: 8px;
border: 1px solid #ddd;
display: none;
}
.mp-main-result {
text-align: center;
margin-bottom: 20px;
padding-bottom: 20px;
border-bottom: 1px solid #eee;
}
.mp-main-result h3 {
margin: 0;
color: #555;
font-size: 18px;
}
.mp-main-result .big-number {
font-size: 42px;
font-weight: 800;
color: #27ae60;
margin: 10px 0;
}
.mp-breakdown {
display: flex;
justify-content: space-between;
flex-wrap: wrap;
}
.mp-breakdown-item {
flex: 1;
min-width: 120px;
text-align: center;
margin: 10px 0;
}
.mp-breakdown-label {
font-size: 13px;
color: #777;
text-transform: uppercase;
letter-spacing: 0.5px;
}
.mp-breakdown-value {
font-size: 18px;
font-weight: 700;
color: #333;
}
.mp-seo-content {
max-width: 800px;
margin: 40px auto;
font-family: 'Segoe UI', Roboto, sans-serif;
line-height: 1.6;
color: #333;
}
.mp-seo-content h2 {
color: #2c3e50;
border-bottom: 2px solid #eee;
padding-bottom: 10px;
margin-top: 30px;
}
.mp-seo-content h3 {
color: #2c3e50;
margin-top: 25px;
}
.mp-seo-content ul {
background: #f4f7f6;
padding: 20px 40px;
border-radius: 5px;
}
.mp-seo-content li {
margin-bottom: 10px;
}
@media (max-width: 600px) {
.mp-calc-grid {
grid-template-columns: 1fr;
}
.mp-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 loanTermYears = parseInt(document.getElementById("loanTerm").value);
var interestRateAnnual = parseFloat(document.getElementById("interestRate").value);
var propertyTaxAnnual = parseFloat(document.getElementById("propertyTax").value);
var homeInsuranceAnnual = parseFloat(document.getElementById("homeInsurance").value);
var hoaFeesMonthly = parseFloat(document.getElementById("hoaFees").value);
// 2. Validate inputs
if (isNaN(homePrice) || isNaN(downPayment) || isNaN(interestRateAnnual) || homePrice <= 0) {
alert("Please enter valid positive numbers for Home Price, Down Payment, and Interest Rate.");
return;
}
// Handle empty optional fields
if (isNaN(propertyTaxAnnual)) propertyTaxAnnual = 0;
if (isNaN(homeInsuranceAnnual)) homeInsuranceAnnual = 0;
if (isNaN(hoaFeesMonthly)) hoaFeesMonthly = 0;
// 3. Logic Calculations
var loanAmount = homePrice – downPayment;
if (loanAmount <= 0) {
alert("Down payment cannot be greater than or equal to the Home Price.");
return;
}
var monthlyInterestRate = (interestRateAnnual / 100) / 12;
var numberOfPayments = loanTermYears * 12;
// Principal and Interest Formula: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
var monthlyPI = 0;
if (interestRateAnnual === 0) {
monthlyPI = loanAmount / numberOfPayments;
} else {
monthlyPI = loanAmount * (monthlyInterestRate * Math.pow(1 + monthlyInterestRate, numberOfPayments)) / (Math.pow(1 + monthlyInterestRate, numberOfPayments) – 1);
}
var monthlyTax = propertyTaxAnnual / 12;
var monthlyInsurance = homeInsuranceAnnual / 12;
var totalMonthly = monthlyPI + monthlyTax + monthlyInsurance + hoaFeesMonthly;
// 4. Update Output
// Helper function for currency formatting
function formatCurrency(num) {
return "$" + num.toFixed(2).replace(/\d(?=(\d{3})+\.)/g, '$&,');
}
document.getElementById("totalMonthlyPayment").innerHTML = formatCurrency(totalMonthly);
document.getElementById("piResult").innerHTML = formatCurrency(monthlyPI);
document.getElementById("taxResult").innerHTML = formatCurrency(monthlyTax);
document.getElementById("insResult").innerHTML = formatCurrency(monthlyInsurance);
document.getElementById("hoaResult").innerHTML = formatCurrency(hoaFeesMonthly);
document.getElementById("loanAmountResult").innerHTML = formatCurrency(loanAmount);
// Show result container
document.getElementById("resultContainer").style.display = "block";
}
Understanding Your Mortgage Payment
Buying a home is one of the largest financial decisions you will make. While the listing price is important, your monthly mortgage payment is the figure that truly determines affordability. This Mortgage Payment Calculator helps you break down the true cost of homeownership, ensuring you aren't caught off guard by hidden expenses like taxes, insurance, and HOA fees.
The 4 Pillars of a Mortgage Payment (PITI)
Lenders often refer to your monthly payment as PITI, which stands for Principal, Interest, Taxes, and Insurance. Understanding these components is critical for financial planning:
- Principal: The portion of your payment that goes directly toward paying down the loan balance (the amount you borrowed). In the early years of a 30-year mortgage, this portion is small but grows over time.
- Interest: The cost of borrowing money. This is paid to the lender. A higher interest rate significantly increases your monthly payment and the total cost of the loan.
- Taxes: Property taxes are assessed by your local government to fund services like schools and roads. These are usually bundled into your monthly payment and held in an escrow account.
- Insurance: Homeowners insurance protects your property against damage. Like taxes, this is typically paid monthly into an escrow account.
How Interest Rates Impact Your Loan
Even a small fluctuation in interest rates can drastically change your buying power. For example, on a $400,000 loan, the difference between a 6% and a 7% interest rate can increase your monthly payment by hundreds of dollars and cost tens of thousands more over the life of the loan. Use the calculator above to test different rate scenarios to see what fits your budget.
Why Include HOA Fees?
Many homebuyers forget to factor in Homeowners Association (HOA) fees. If you are buying a condo, townhouse, or a home in a planned community, these mandatory monthly fees are paid separately from your mortgage but directly affect your debt-to-income ratio (DTI). Always include these in your calculation to get an accurate picture of your monthly outgoing cash flow.
Frequently Asked Questions
What is a good down payment?
While 20% is the gold standard to avoid Private Mortgage Insurance (PMI), many buyers qualify for loans with as little as 3% or 3.5% down (FHA loans). However, a smaller down payment results in a larger loan amount and higher monthly payments.
Does this calculator include PMI?
This calculator focuses on PITI and HOA. If your down payment is less than 20%, you may also be required to pay Private Mortgage Insurance, which typically costs between 0.5% and 1% of the loan amount annually.
How can I lower my monthly payment?
To reduce your monthly burden, you can increase your down payment, shop around for a lower interest rate, choose a longer loan term (e.g., 30 years vs. 15 years), or buy a less expensive home to reduce the principal balance.