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.mc-col { flex: 1; min-width: 200px; }
.mc-label { display: block; margin-bottom: 5px; font-weight: 600; color: #333; font-size: 14px; }
.mc-input { width: 100%; padding: 10px; border: 1px solid #ddd; border-radius: 4px; font-size: 16px; box-sizing: border-box; }
.mc-input:focus { border-color: #0073aa; outline: none; }
.mc-btn { width: 100%; padding: 15px; background-color: #0073aa; color: white; border: none; border-radius: 4px; font-size: 18px; font-weight: bold; cursor: pointer; transition: background 0.3s; margin-top: 10px; }
.mc-btn:hover { background-color: #005177; }
.mc-result-box { margin-top: 25px; padding: 20px; background-color: #f8f9fa; border-left: 5px solid #0073aa; display: none; }
.mc-result-row { display: flex; justify-content: space-between; margin-bottom: 10px; padding-bottom: 10px; border-bottom: 1px solid #eee; }
.mc-result-row:last-child { border-bottom: none; margin-bottom: 0; }
.mc-result-label { font-weight: 600; color: #555; }
.mc-result-value { font-weight: bold; color: #333; font-size: 18px; }
.mc-total-highlight { font-size: 24px; color: #0073aa; }
.mc-error { color: #dc3232; margin-top: 10px; display: none; font-weight: bold; }
.seo-content { margin-top: 40px; line-height: 1.6; color: #444; }
.seo-content h2 { color: #23282d; margin-top: 30px; }
.seo-content h3 { color: #23282d; margin-top: 20px; font-size: 18px; }
.seo-content p { margin-bottom: 15px; }
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function calculateMortgage() {
// Get inputs by ID matches EXACTLY
var homePrice = parseFloat(document.getElementById("homePrice").value);
var downPayment = parseFloat(document.getElementById("downPayment").value);
var interestRate = parseFloat(document.getElementById("interestRate").value);
var loanTerm = parseFloat(document.getElementById("loanTerm").value);
var propertyTax = parseFloat(document.getElementById("propertyTax").value);
var homeInsurance = parseFloat(document.getElementById("homeInsurance").value);
var errorDiv = document.getElementById("mcError");
var resultBox = document.getElementById("mcResults");
// Validation
if (isNaN(homePrice) || isNaN(downPayment) || isNaN(interestRate) || isNaN(loanTerm) || isNaN(propertyTax) || isNaN(homeInsurance) || loanTerm <= 0) {
errorDiv.style.display = "block";
resultBox.style.display = "none";
return;
}
errorDiv.style.display = "none";
// Core Calculations
var principal = homePrice – downPayment;
var monthlyRate = (interestRate / 100) / 12;
var numberOfPayments = loanTerm * 12;
// Mortgage Formula: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
var monthlyPrincipalInterest = 0;
if (interestRate === 0) {
monthlyPrincipalInterest = principal / numberOfPayments;
} else {
monthlyPrincipalInterest = principal * (monthlyRate * Math.pow(1 + monthlyRate, numberOfPayments)) / (Math.pow(1 + monthlyRate, numberOfPayments) – 1);
}
var monthlyTax = propertyTax / 12;
var monthlyInsurance = homeInsurance / 12;
var monthlyEscrow = monthlyTax + monthlyInsurance;
var totalMonthlyPayment = monthlyPrincipalInterest + monthlyEscrow;
var totalCost = (monthlyPrincipalInterest * numberOfPayments) + downPayment; // Total cost of home acquisition via loan terms (excluding tax/ins over time as those vary)
// Actually standard Total Cost of Loan usually refers to Total Principal + Total Interest
var totalLoanPayment = monthlyPrincipalInterest * numberOfPayments;
var totalInterest = totalLoanPayment – principal;
// Payoff Date Calculation
var today = new Date();
var payoffDate = new Date(today.setMonth(today.getMonth() + numberOfPayments));
var payoffMonthYear = payoffDate.toLocaleString('default', { month: 'long', year: 'numeric' });
// Format Currency
var formatter = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
});
// Update Result Elements with Valid Logic
document.getElementById("resPrincipal").innerHTML = formatter.format(monthlyPrincipalInterest);
document.getElementById("resEscrow").innerHTML = formatter.format(monthlyEscrow);
document.getElementById("resTotalMonthly").innerHTML = formatter.format(totalMonthlyPayment);
document.getElementById("resTotalInterest").innerHTML = formatter.format(totalInterest);
document.getElementById("resTotalCost").innerHTML = formatter.format(totalLoanPayment);
document.getElementById("resPayoffDate").innerHTML = payoffMonthYear;
// Show Results
resultBox.style.display = "block";
}
Mortgage Payment Calculator
Please enter valid numeric values for all fields.
Principal & Interest:
$0.00
Monthly Tax & Insurance:
$0.00
Total Monthly Payment:
$0.00
Total Interest Paid:
$0.00
Total Cost of Loan:
$0.00
Payoff Date:
Month Year
Understanding Your Mortgage Payment
Before committing to a home purchase, it is crucial to understand exactly what your monthly financial obligation will be. This Mortgage Payment Calculator helps you estimate your monthly payments by accounting for the four primary components of a mortgage payment: Principal, Interest, Taxes, and Insurance (often referred to as PITI).
How the Calculation Works
While the calculation of your core mortgage payment (Principal and Interest) uses a standard amortization formula, the "real" check you write every month includes other factors:
- Principal: The portion of your payment that reduces the loan balance.
- Interest: The cost of borrowing money, calculated based on your annual percentage rate (APR).
- Escrow Costs: Most lenders require you to pay 1/12th of your annual property taxes and homeowners insurance each month. These funds are held in an escrow account.
Example Calculation
Consider buying a home listed at $350,000. If you make a 20% down payment ($70,000), you are financing $280,000. With a 30-year fixed-rate mortgage at 6.5% interest:
- Your Principal & Interest payment would be approximately $1,770 per month.
- If annual taxes are $4,000 and insurance is $1,200, you add roughly $433 per month for escrow.
- Your total monthly payment would be roughly $2,203.
- Over the life of the loan, you would pay over $357,000 in interest alone.
Use the tool above to adjust these numbers based on your specific loan offer and local tax rates to find a monthly budget that works for you.