#mortgage-calculator-container {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
max-width: 800px;
margin: 0 auto;
padding: 20px;
background: #ffffff;
border: 1px solid #e0e0e0;
border-radius: 8px;
box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}
.mc-header {
text-align: center;
margin-bottom: 30px;
}
.mc-header h2 {
color: #2c3e50;
margin-bottom: 10px;
font-size: 28px;
}
.mc-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 20px;
}
@media (max-width: 600px) {
.mc-grid {
grid-template-columns: 1fr;
}
}
.mc-input-group {
margin-bottom: 15px;
}
.mc-input-group label {
display: block;
margin-bottom: 8px;
color: #34495e;
font-weight: 600;
font-size: 14px;
}
.mc-input-group input, .mc-input-group select {
width: 100%;
padding: 12px;
border: 1px solid #cbd5e0;
border-radius: 6px;
font-size: 16px;
box-sizing: border-box;
transition: border-color 0.3s;
}
.mc-input-group input:focus {
border-color: #3498db;
outline: none;
}
.mc-btn-container {
grid-column: 1 / -1;
text-align: center;
margin-top: 10px;
}
.mc-btn {
background-color: #27ae60;
color: white;
border: none;
padding: 15px 40px;
font-size: 18px;
font-weight: bold;
border-radius: 6px;
cursor: pointer;
transition: background-color 0.3s;
}
.mc-btn:hover {
background-color: #219150;
}
.mc-results {
margin-top: 30px;
background-color: #f8f9fa;
padding: 25px;
border-radius: 8px;
display: none;
border-left: 5px solid #27ae60;
}
.mc-result-row {
display: flex;
justify-content: space-between;
margin-bottom: 12px;
font-size: 16px;
color: #555;
padding-bottom: 8px;
border-bottom: 1px dashed #ddd;
}
.mc-result-row:last-child {
border-bottom: none;
}
.mc-result-main {
text-align: center;
margin-bottom: 25px;
padding-bottom: 15px;
border-bottom: 2px solid #e0e0e0;
}
.mc-result-main h3 {
margin: 0 0 10px 0;
color: #7f8c8d;
font-size: 16px;
text-transform: uppercase;
letter-spacing: 1px;
}
.mc-result-main .big-price {
font-size: 42px;
color: #2c3e50;
font-weight: 800;
}
.mc-article {
margin-top: 50px;
line-height: 1.6;
color: #444;
}
.mc-article h3 {
color: #2c3e50;
border-bottom: 2px solid #eee;
padding-bottom: 10px;
margin-top: 30px;
}
.mc-article ul {
padding-left: 20px;
}
.mc-article li {
margin-bottom: 10px;
}
function calculateMortgage() {
// 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 annualTax = parseFloat(document.getElementById("propertyTax").value);
var annualIns = parseFloat(document.getElementById("homeInsurance").value);
var monthlyHOA = parseFloat(document.getElementById("hoaFees").value);
// Validation to prevent errors
if (isNaN(homePrice) || homePrice <= 0) homePrice = 0;
if (isNaN(downPayment) || downPayment < 0) downPayment = 0;
if (isNaN(interestRate) || interestRate < 0) interestRate = 0;
if (isNaN(annualTax) || annualTax < 0) annualTax = 0;
if (isNaN(annualIns) || annualIns < 0) annualIns = 0;
if (isNaN(monthlyHOA) || monthlyHOA < 0) monthlyHOA = 0;
// Derived Variables
var principal = homePrice – downPayment;
// If principal is zero or less, handle gracefully
if (principal <= 0) {
document.getElementById("mcResults").style.display = "block";
document.getElementById("totalMonthlyDisplay").innerText = "$0.00";
return;
}
var monthlyRate = (interestRate / 100) / 12;
var numberOfPayments = loanTermYears * 12;
// Calculate Principal & Interest (P&I)
var monthlyPI = 0;
if (interestRate === 0) {
monthlyPI = principal / numberOfPayments;
} else {
monthlyPI = principal * (monthlyRate * Math.pow(1 + monthlyRate, numberOfPayments)) / (Math.pow(1 + monthlyRate, numberOfPayments) – 1);
}
// Calculate Escrow Components
var monthlyTax = annualTax / 12;
var monthlyIns = annualIns / 12;
// Total Monthly Payment
var totalMonthlyPayment = monthlyPI + monthlyTax + monthlyIns + monthlyHOA;
// Total Stats
var totalPaymentOverLife = (monthlyPI * numberOfPayments);
var totalInterest = totalPaymentOverLife – principal;
// Calculate Payoff Date
var today = new Date();
var payoffYear = today.getFullYear() + loanTermYears;
var monthNames = ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"];
var payoffDateStr = monthNames[today.getMonth()] + " " + payoffYear;
// Currency Formatter
var formatter = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
minimumFractionDigits: 2
});
// Update UI
document.getElementById("piDisplay").innerText = formatter.format(monthlyPI);
document.getElementById("taxDisplay").innerText = formatter.format(monthlyTax);
document.getElementById("insDisplay").innerText = formatter.format(monthlyIns);
document.getElementById("hoaDisplay").innerText = formatter.format(monthlyHOA);
document.getElementById("totalMonthlyDisplay").innerText = formatter.format(totalMonthlyPayment);
document.getElementById("loanAmountDisplay").innerText = formatter.format(principal);
document.getElementById("totalInterestDisplay").innerText = formatter.format(totalInterest);
document.getElementById("payoffDateDisplay").innerText = payoffDateStr;
// Show Results Container
document.getElementById("mcResults").style.display = "block";
}
Mortgage Payment Calculator
Estimate your monthly payments, including taxes, insurance, and HOA fees.
30 Years
20 Years
15 Years
10 Years
Total Monthly Payment
$0.00
Principal & Interest:
$0.00
Property Tax (Monthly):
$0.00
Home Insurance (Monthly):
$0.00
HOA Fees (Monthly):
$0.00
Loan Amount:
$0.00
Total Interest Paid (Over Life of Loan):
$0.00
Payoff Date:
–
How to Calculate Your Monthly Mortgage Payment
Understanding exactly how much house you can afford begins with calculating your monthly mortgage payment. While the sticker price of a home is important, the monthly cash flow requirement is what affects your daily budget. This calculator uses the standard amortization formula used by lenders to determine your Principal and Interest (P&I) payments.
The core formula used for the calculation is:
M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
Where:
- M = Total monthly P&I payment
- P = The principal loan amount (Home Price minus Down Payment)
- i = Monthly interest rate (Annual Rate divided by 12)
- n = Number of payments over the loan's lifetime (Years multiplied by 12)
The Components of Your Payment (PITI)
Most mortgage payments consist of four parts, commonly referred to as PITI:
- Principal: The money that goes directly towards paying down your loan balance. In the early years of a mortgage, this portion is small.
- Interest: The cost of borrowing money. In the beginning of a 30-year term, the majority 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.
- Insurance: Homeowners insurance protects your property against damage. Like taxes, this is often escrowed.
Why Include HOA Fees?
If you are buying a condo or a home in a planned community, you will likely pay Homeowners Association (HOA) fees. While these are usually paid directly to the association and not the lender, they are a critical part of your Debt-to-Income (DTI) ratio and monthly affordability. Our calculator adds this to give you a true "out-of-pocket" monthly cost.