.calc-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 20px;
}
@media (max-width: 600px) {
.calc-grid {
grid-template-columns: 1fr;
}
}
.calc-input-group {
margin-bottom: 15px;
}
.calc-label {
display: block;
margin-bottom: 5px;
font-weight: 600;
color: #333;
font-size: 14px;
}
.calc-input {
width: 100%;
padding: 10px;
border: 1px solid #ccc;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
}
.calc-btn {
background-color: #0073aa;
color: white;
border: none;
padding: 12px 20px;
font-size: 16px;
font-weight: bold;
border-radius: 4px;
cursor: pointer;
width: 100%;
margin-top: 10px;
transition: background-color 0.3s;
}
.calc-btn:hover {
background-color: #005177;
}
.calc-results {
background-color: #f7f9fc;
padding: 20px;
border-radius: 8px;
margin-top: 25px;
border-left: 5px solid #0073aa;
display: none;
}
.calc-result-row {
display: flex;
justify-content: space-between;
margin-bottom: 10px;
font-size: 15px;
}
.calc-result-row.total {
border-top: 1px solid #ddd;
padding-top: 10px;
font-weight: bold;
font-size: 18px;
color: #0073aa;
}
.calc-error {
color: #d32f2f;
font-size: 14px;
margin-top: 10px;
display: none;
}
.article-content {
margin-top: 40px;
line-height: 1.6;
color: #444;
}
.article-content h2 { color: #23282d; margin-top: 30px; }
.article-content h3 { color: #23282d; }
.article-content ul { padding-left: 20px; }
function calculateMortgage() {
// Get Input Values
var price = parseFloat(document.getElementById('mcHomePrice').value);
var downPayment = parseFloat(document.getElementById('mcDownPayment').value);
var interestRate = parseFloat(document.getElementById('mcInterestRate').value);
var termYears = parseInt(document.getElementById('mcLoanTerm').value);
var annualTax = parseFloat(document.getElementById('mcPropertyTax').value);
var annualInsurance = parseFloat(document.getElementById('mcHomeInsurance').value);
var monthlyHOA = parseFloat(document.getElementById('mcHOA').value);
var errorDiv = document.getElementById('mcError');
var resultsDiv = document.getElementById('mcResults');
// Basic Validation
if (isNaN(price) || isNaN(downPayment) || isNaN(interestRate) || isNaN(termYears) ||
isNaN(annualTax) || isNaN(annualInsurance) || isNaN(monthlyHOA)) {
errorDiv.style.display = 'block';
resultsDiv.style.display = 'none';
return;
}
errorDiv.style.display = 'none';
// Calculations
var loanAmount = price – downPayment;
if (loanAmount <= 0) {
alert("Down payment cannot be greater than or equal to Home Price.");
return;
}
// Monthly Interest Rate
var monthlyRate = (interestRate / 100) / 12;
// Total Number of Payments
var numberOfPayments = termYears * 12;
// Monthly Principal & Interest Calculation
var monthlyPI = 0;
if (interestRate === 0) {
monthlyPI = loanAmount / numberOfPayments;
} else {
monthlyPI = loanAmount * (monthlyRate * Math.pow(1 + monthlyRate, numberOfPayments)) / (Math.pow(1 + monthlyRate, numberOfPayments) – 1);
}
// Tax and Insurance components
var monthlyTax = annualTax / 12;
var monthlyInsurance = annualInsurance / 12;
// Total Monthly Payment (PITI + HOA)
var totalMonthlyPayment = monthlyPI + monthlyTax + monthlyInsurance + monthlyHOA;
// Total Loan Costs
var totalPaidOverTerm = (monthlyPI * numberOfPayments);
var totalInterest = totalPaidOverTerm – loanAmount;
// Display Results
document.getElementById('resPrincipalInterest').innerText = '$' + monthlyPI.toFixed(2).replace(/\B(?=(\d{3})+(?!\d))/g, ",");
document.getElementById('resTax').innerText = '$' + monthlyTax.toFixed(2).replace(/\B(?=(\d{3})+(?!\d))/g, ",");
document.getElementById('resInsurance').innerText = '$' + monthlyInsurance.toFixed(2).replace(/\B(?=(\d{3})+(?!\d))/g, ",");
document.getElementById('resHOA').innerText = '$' + monthlyHOA.toFixed(2).replace(/\B(?=(\d{3})+(?!\d))/g, ",");
document.getElementById('resTotal').innerText = '$' + totalMonthlyPayment.toFixed(2).replace(/\B(?=(\d{3})+(?!\d))/g, ",");
document.getElementById('resLoanAmount').innerText = '$' + loanAmount.toFixed(0).replace(/\B(?=(\d{3})+(?!\d))/g, ",");
document.getElementById('resTotalInterest').innerText = '$' + totalInterest.toFixed(0).replace(/\B(?=(\d{3})+(?!\d))/g, ",");
document.getElementById('resTotalCost').innerText = '$' + totalPaidOverTerm.toFixed(0).replace(/\B(?=(\d{3})+(?!\d))/g, ",");
resultsDiv.style.display = 'block';
}
Advanced Mortgage Calculator (PITI)
30 Years
20 Years
15 Years
10 Years
Please enter valid numeric values for all fields.
Estimated Monthly Payment Breakdown
Principal & Interest:
$0.00
Property Tax:
$0.00
Home Insurance:
$0.00
HOA Fees:
$0.00
Total Monthly Payment (PITI):
$0.00
Loan Summary:
Loan Amount:
Total Interest Paid over Term:
Total Cost of Loan:
Loan Amount:
Total Interest Paid over Term:
Total Cost of Loan:
Understanding Your Mortgage Calculation
Buying a home is often the largest financial decision a person makes. Our Advanced Mortgage Calculator goes beyond simple principal and interest calculations to give you a realistic view of your monthly housing costs, often referred to as PITI (Principal, Interest, Taxes, and Insurance).
What is PITI?
When lenders assess your ability to repay a loan, they look at the total PITI figure:
- Principal: The portion of your payment that pays down the loan balance.
- Interest: The cost of borrowing the money, paid to the lender.
- Taxes: Property taxes assessed by your local government, typically held in escrow.
- Insurance: Homeowners insurance to protect against damage, also usually held in escrow.
Additionally, if you buy a condo or a home in a planned community, you must account for HOA (Homeowners Association) fees, which are paid separately but impact your monthly affordability.
How Interest Rates Affect Buying Power
Even a small change in interest rates can significantly impact your monthly payment. For example, on a $300,000 loan, the difference between a 6.0% and a 7.0% interest rate can increase your monthly payment by nearly $200 over a 30-year term. Using this calculator allows you to test different rate scenarios to see what fits your budget.
The Impact of the Down Payment
Your down payment reduces the Loan-to-Value (LTV) ratio. A higher down payment not only reduces your monthly principal and interest payment but can also help you avoid Private Mortgage Insurance (PMI) if you put down 20% or more. Note that this calculator focuses on PITI and HOA; if your down payment is less than 20%, you should check with your lender about additional PMI costs.
How to Use This Calculator
- Enter Home Price: The purchase price of the property.
- Enter Down Payment: Cash you are paying upfront.
- Set Interest Rate & Term: Enter current market rates and choose between 10, 15, 20, or 30-year terms.
- Add Recurring Costs: Input annual property taxes, insurance estimates, and any monthly HOA fees for the most accurate result.