#mortgage-calc-wrapper .calc-container {
background: #ffffff;
border: 1px solid #e2e8f0;
border-radius: 8px;
padding: 25px;
box-shadow: 0 4px 6px rgba(0,0,0,0.05);
margin-bottom: 40px;
}
#mortgage-calc-wrapper .input-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 20px;
}
@media (max-width: 600px) {
#mortgage-calc-wrapper .input-grid {
grid-template-columns: 1fr;
}
}
#mortgage-calc-wrapper .input-group {
margin-bottom: 15px;
}
#mortgage-calc-wrapper label {
display: block;
font-weight: 600;
margin-bottom: 8px;
font-size: 14px;
color: #4a5568;
}
#mortgage-calc-wrapper input, #mortgage-calc-wrapper select {
width: 100%;
padding: 10px 12px;
border: 1px solid #cbd5e0;
border-radius: 6px;
font-size: 16px;
box-sizing: border-box;
transition: border-color 0.2s;
}
#mortgage-calc-wrapper input:focus {
border-color: #3182ce;
outline: none;
box-shadow: 0 0 0 3px rgba(49, 130, 206, 0.1);
}
#mortgage-calc-wrapper .calc-btn {
background-color: #2b6cb0;
color: white;
border: none;
padding: 12px 24px;
font-size: 16px;
font-weight: bold;
border-radius: 6px;
cursor: pointer;
width: 100%;
margin-top: 10px;
transition: background-color 0.2s;
}
#mortgage-calc-wrapper .calc-btn:hover {
background-color: #2c5282;
}
#mortgage-calc-wrapper .results-box {
background-color: #f7fafc;
border: 1px solid #edf2f7;
border-radius: 8px;
padding: 20px;
margin-top: 25px;
display: none;
}
#mortgage-calc-wrapper .results-header {
text-align: center;
border-bottom: 2px solid #e2e8f0;
padding-bottom: 15px;
margin-bottom: 15px;
}
#mortgage-calc-wrapper .main-result {
font-size: 36px;
font-weight: 800;
color: #2b6cb0;
}
#mortgage-calc-wrapper .sub-result-text {
color: #718096;
font-size: 14px;
text-transform: uppercase;
letter-spacing: 0.5px;
}
#mortgage-calc-wrapper .breakdown-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 15px;
}
#mortgage-calc-wrapper .breakdown-item {
background: white;
padding: 10px;
border-radius: 6px;
border: 1px solid #e2e8f0;
}
#mortgage-calc-wrapper .breakdown-label {
font-size: 13px;
color: #718096;
}
#mortgage-calc-wrapper .breakdown-value {
font-size: 16px;
font-weight: 600;
color: #2d3748;
}
#mortgage-calc-wrapper .article-content h2 {
font-size: 24px;
margin-top: 30px;
color: #2d3748;
}
#mortgage-calc-wrapper .article-content h3 {
font-size: 20px;
margin-top: 25px;
color: #4a5568;
}
#mortgage-calc-wrapper .article-content p {
line-height: 1.6;
margin-bottom: 15px;
color: #4a5568;
}
#mortgage-calc-wrapper .article-content ul {
padding-left: 20px;
color: #4a5568;
margin-bottom: 15px;
}
#mortgage-calc-wrapper .article-content li {
margin-bottom: 8px;
}
// Set default date to today
var today = new Date();
var dd = String(today.getDate()).padStart(2, '0');
var mm = String(today.getMonth() + 1).padStart(2, '0');
var yyyy = today.getFullYear();
document.getElementById('startDate').value = yyyy + '-' + mm + '-' + dd;
function calculateMortgage() {
// Get inputs
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 annualInsurance = parseFloat(document.getElementById('homeInsurance').value);
var monthlyHOA = parseFloat(document.getElementById('hoaFees').value);
var startDateVal = document.getElementById('startDate').value;
// Validate inputs
if (isNaN(homePrice) || isNaN(downPayment) || isNaN(interestRate) || isNaN(loanTermYears)) {
alert("Please enter valid numbers for the loan details.");
return;
}
if (isNaN(annualTax)) annualTax = 0;
if (isNaN(annualInsurance)) annualInsurance = 0;
if (isNaN(monthlyHOA)) monthlyHOA = 0;
// Calculations
var principal = homePrice – downPayment;
// Handle edge case where principal is 0 or less
if (principal <= 0) {
alert("Down payment cannot be equal to or greater than home price for a mortgage calculation.");
return;
}
var monthlyRate = (interestRate / 100) / 12;
var numberOfPayments = loanTermYears * 12;
// Mortgage Formula: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
var monthlyPI = 0;
if (interestRate === 0) {
monthlyPI = principal / numberOfPayments;
} else {
monthlyPI = principal * (monthlyRate * Math.pow(1 + monthlyRate, numberOfPayments)) / (Math.pow(1 + monthlyRate, numberOfPayments) – 1);
}
var monthlyTax = annualTax / 12;
var monthlyInsurance = annualInsurance / 12;
var totalMonthlyPayment = monthlyPI + monthlyTax + monthlyInsurance + monthlyHOA;
var totalCost = monthlyPI * numberOfPayments;
var totalInterest = totalCost – principal;
// Calculate Payoff Date
var start = new Date(startDateVal);
start.setMonth(start.getMonth() + numberOfPayments);
var payoffMonth = start.toLocaleString('default', { month: 'short' });
var payoffYear = start.getFullYear();
var payoffString = payoffMonth + " " + payoffYear;
// Formatting currency
var formatter = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
minimumFractionDigits: 2
});
// Display Results
document.getElementById('monthlyTotalDisplay').innerText = formatter.format(totalMonthlyPayment);
document.getElementById('piDisplay').innerText = formatter.format(monthlyPI);
document.getElementById('loanAmountDisplay').innerText = formatter.format(principal);
document.getElementById('totalInterestDisplay').innerText = formatter.format(totalInterest);
document.getElementById('taxDisplay').innerText = formatter.format(monthlyTax);
document.getElementById('insuranceDisplay').innerText = formatter.format(monthlyInsurance);
document.getElementById('payoffDateDisplay').innerText = payoffString;
// Show results container
document.getElementById('resultBox').style.display = 'block';
}
Mortgage Payment Calculator
30 Years
20 Years
15 Years
10 Years
Estimated Monthly Payment
$0.00
Principal & Interest
$0.00
Loan Amount
$0.00
Total Interest Paid
$0.00
Payoff Date
–
Property Tax (Monthly)
$0.00
Insurance (Monthly)
$0.00
How Mortgage Payments Are Calculated
Understanding how your monthly mortgage payment is determined is a crucial step in the home buying process. While the headline number often refers to Principal and Interest (P&I), the actual amount leaving your bank account each month typically includes taxes, insurance, and sometimes homeowner association (HOA) fees. This calculator breaks down all these components to give you a realistic "out-the-door" monthly cost.
Components of a Mortgage Payment (PITI)
Lenders often refer to your monthly payment as PITI, which stands for:
- Principal: The portion of your payment that goes directly toward paying down the loan balance ($350,000 home – $70,000 down = $280,000 principal).
- Interest: The cost of borrowing money. In the early years of a standard 30-year mortgage, the majority of your payment goes toward interest rather than principal.
- Taxes: Property taxes assessed by your local government. Lenders usually collect this monthly and hold it in an escrow account to pay the bill annually.
- Insurance: Homeowners insurance protects the property against damage. Like taxes, this is often collected monthly in escrow.
How Interest Rates Affect Buying Power
Even a small change in interest rates can significantly impact your monthly payment and total loan cost. For example, on a $300,000 loan, the difference between a 6.0% and a 7.0% interest rate is roughly $200 per month. Over the life of a 30-year loan, that 1% difference costs nearly $72,000 in additional interest.
What is Amortization?
Mortgages use an amortization schedule to ensure the loan is paid off by the end of the term. In the beginning, your payments are interest-heavy. As time passes, the principal portion of your payment increases while the interest portion decreases. This calculator estimates your total interest paid and your projected payoff date based on the term you select (typically 15 or 30 years).
Budgeting for "Hidden" Costs
Don't forget to factor in HOA fees if you are buying a condo or a home in a planned community. While these fees aren't part of the loan itself, lenders factor them into your Debt-to-Income (DTI) ratio to determine if you qualify for the mortgage. Unlike taxes and insurance, HOA fees are usually paid directly to the association, not through your mortgage servicer, but they are included in this calculator to help you budget effectively.