.calc-container-wrapper {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
max-width: 800px;
margin: 20px auto;
padding: 20px;
background: #ffffff;
border: 1px solid #e0e0e0;
border-radius: 8px;
box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}
.calc-input-group {
margin-bottom: 20px;
}
.calc-row {
display: flex;
flex-wrap: wrap;
gap: 20px;
}
.calc-col {
flex: 1;
min-width: 250px;
}
.calc-label {
display: block;
margin-bottom: 8px;
font-weight: 600;
color: #333;
font-size: 14px;
}
.calc-input {
width: 100%;
padding: 10px 12px;
border: 1px solid #ccc;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
transition: border-color 0.3s;
}
.calc-input:focus {
border-color: #007bff;
outline: none;
}
.calc-btn {
display: block;
width: 100%;
padding: 12px;
background-color: #007bff;
color: white;
border: none;
border-radius: 4px;
font-size: 16px;
font-weight: bold;
cursor: pointer;
transition: background-color 0.2s;
margin-top: 10px;
}
.calc-btn:hover {
background-color: #0056b3;
}
.calc-results {
margin-top: 30px;
background: #f8f9fa;
padding: 20px;
border-radius: 6px;
border-left: 5px solid #007bff;
display: none;
}
.result-main {
font-size: 32px;
font-weight: bold;
color: #007bff;
margin-bottom: 5px;
}
.result-label-main {
font-size: 14px;
color: #666;
margin-bottom: 20px;
text-transform: uppercase;
letter-spacing: 1px;
}
.breakdown-row {
display: flex;
justify-content: space-between;
padding: 8px 0;
border-bottom: 1px solid #e9ecef;
font-size: 14px;
}
.breakdown-row:last-child {
border-bottom: none;
}
.breakdown-val {
font-weight: 600;
color: #333;
}
.calc-article {
margin-top: 40px;
line-height: 1.6;
color: #333;
}
.calc-article h2 {
font-size: 24px;
margin-top: 30px;
margin-bottom: 15px;
color: #2c3e50;
}
.calc-article p {
margin-bottom: 15px;
}
.calc-article ul {
margin-bottom: 15px;
padding-left: 20px;
}
.calc-article li {
margin-bottom: 8px;
}
function calculateMortgage() {
// Get Input Values
var homePrice = parseFloat(document.getElementById("homePrice").value);
var downPayment = parseFloat(document.getElementById("downPayment").value);
var loanTermYears = parseFloat(document.getElementById("loanTerm").value);
var annualInterestRate = 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);
// Validation
if (isNaN(homePrice) || homePrice <= 0) {
alert("Please enter a valid Home Price.");
return;
}
if (isNaN(downPayment) || downPayment < 0) downPayment = 0;
if (isNaN(loanTermYears) || loanTermYears <= 0) loanTermYears = 30;
if (isNaN(annualInterestRate) || annualInterestRate < 0) annualInterestRate = 0;
if (isNaN(propertyTaxAnnual) || propertyTaxAnnual < 0) propertyTaxAnnual = 0;
if (isNaN(homeInsuranceAnnual) || homeInsuranceAnnual < 0) homeInsuranceAnnual = 0;
if (isNaN(hoaFeesMonthly) || hoaFeesMonthly < 0) hoaFeesMonthly = 0;
// Calculations
var principal = homePrice – downPayment;
var monthlyInterestRate = (annualInterestRate / 100) / 12;
var numberOfPayments = loanTermYears * 12;
var monthlyPI = 0;
if (principal <= 0) {
monthlyPI = 0;
} else if (annualInterestRate === 0) {
monthlyPI = principal / numberOfPayments;
} else {
// Formula: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1]
var pow = Math.pow(1 + monthlyInterestRate, numberOfPayments);
monthlyPI = principal * ((monthlyInterestRate * pow) / (pow – 1));
}
var monthlyTax = propertyTaxAnnual / 12;
var monthlyInsurance = homeInsuranceAnnual / 12;
var totalMonthly = monthlyPI + monthlyTax + monthlyInsurance + hoaFeesMonthly;
// Formatting Output
var formatter = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
});
// Display Results
document.getElementById("mortgageResults").style.display = "block";
document.getElementById("totalMonthlyPayment").innerText = formatter.format(totalMonthly);
document.getElementById("piPayment").innerText = formatter.format(monthlyPI);
document.getElementById("taxPayment").innerText = formatter.format(monthlyTax);
document.getElementById("insPayment").innerText = formatter.format(monthlyInsurance);
document.getElementById("hoaPayment").innerText = formatter.format(hoaFeesMonthly);
document.getElementById("totalLoanAmount").innerText = formatter.format(principal);
}
Mortgage Payment Calculator
Estimated Monthly Payment
$0.00
Principal & Interest
$0.00
Property Tax
$0.00
Homeowners Insurance
$0.00
HOA Fees
$0.00
Total Loan Amount
$0.00
How to Use This Mortgage Calculator
Purchasing a home is one of the biggest financial decisions you will make. This Mortgage Payment Calculator helps you estimate your monthly financial commitment by factoring in principal, interest, taxes, and insurance (PITI).
Simply enter the home price, your planned down payment, the loan term (usually 15 or 30 years), and your expected interest rate. For a more accurate estimate, include annual property taxes, home insurance premiums, and any applicable Homeowners Association (HOA) fees.
Understanding Your Monthly Payment Breakdown
Your monthly mortgage payment is typically composed of four main parts:
- Principal: The portion of your payment that goes toward paying down the borrowed amount.
- Interest: The cost of borrowing money from your lender.
- Taxes: Property taxes collected by your local government, often bundled into your monthly mortgage bill.
- Insurance: Homeowners insurance protects your property against damage and is usually required by lenders.
The Mortgage Formula Explained
This calculator uses the standard amortization formula to determine the principal and interest portion of your payment:
M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
Where:
- M = Total monthly principal and interest payment
- P = Principal loan amount (Home Price minus Down Payment)
- i = Monthly interest rate (Annual Rate divided by 12)
- n = Number of payments (Loan Term in years multiplied by 12)
Taxes, insurance, and HOA fees are then added to this figure to provide your comprehensive estimated monthly housing cost.