.calculator-wrapper {
max-width: 800px;
margin: 0 auto;
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
line-height: 1.6;
color: #333;
}
.calc-container {
background: #f9f9f9;
border: 1px solid #e0e0e0;
border-radius: 8px;
padding: 25px;
margin-bottom: 40px;
box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}
.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-input-group label {
display: block;
margin-bottom: 5px;
font-weight: 600;
font-size: 14px;
}
.calc-input-group input, .calc-input-group select {
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 24px;
font-size: 16px;
font-weight: bold;
border-radius: 4px;
cursor: pointer;
width: 100%;
transition: background-color 0.3s;
margin-top: 10px;
}
.calc-btn:hover {
background-color: #005177;
}
.calc-results {
margin-top: 25px;
padding-top: 20px;
border-top: 2px solid #eee;
display: none;
}
.calc-result-row {
display: flex;
justify-content: space-between;
margin-bottom: 10px;
font-size: 16px;
}
.calc-result-row.total {
font-size: 20px;
font-weight: 800;
color: #0073aa;
margin-top: 15px;
padding-top: 10px;
border-top: 1px dashed #ccc;
}
.calc-content {
margin-top: 40px;
}
.calc-content h2 {
font-size: 24px;
margin-bottom: 15px;
color: #2c3e50;
}
.calc-content h3 {
font-size: 20px;
margin-top: 20px;
margin-bottom: 10px;
color: #34495e;
}
.calc-content p {
margin-bottom: 15px;
}
.calc-content ul {
margin-bottom: 15px;
padding-left: 20px;
}
.error-msg {
color: red;
font-size: 14px;
margin-top: 5px;
display: none;
}
function calculateMortgage() {
// Get Input Values
var homePrice = parseFloat(document.getElementById('mc-home-price').value);
var downPayment = parseFloat(document.getElementById('mc-down-payment').value);
var interestRate = parseFloat(document.getElementById('mc-interest-rate').value);
var termYears = parseInt(document.getElementById('mc-loan-term').value);
var annualTax = parseFloat(document.getElementById('mc-property-tax').value);
var annualIns = parseFloat(document.getElementById('mc-insurance').value);
var errorDiv = document.getElementById('mc-error');
var resultsDiv = document.getElementById('mc-results');
// Validate Inputs
if (isNaN(homePrice) || isNaN(downPayment) || isNaN(interestRate) ||
isNaN(termYears) || isNaN(annualTax) || isNaN(annualIns) ||
homePrice < 0 || interestRate < 0) {
errorDiv.style.display = 'block';
resultsDiv.style.display = 'none';
return;
}
errorDiv.style.display = 'none';
// Core Logic
var principal = homePrice – downPayment;
var monthlyRate = (interestRate / 100) / 12;
var numberOfPayments = termYears * 12;
var monthlyPI = 0;
// Handle 0% interest edge case
if (interestRate === 0) {
monthlyPI = principal / numberOfPayments;
} else {
// Mortgage Formula: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1]
monthlyPI = (principal * monthlyRate * Math.pow(1 + monthlyRate, numberOfPayments)) /
(Math.pow(1 + monthlyRate, numberOfPayments) – 1);
}
var monthlyTax = annualTax / 12;
var monthlyIns = annualIns / 12;
var totalMonthly = monthlyPI + monthlyTax + monthlyIns;
// Formatting Function
var formatter = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
});
// Output Results
document.getElementById('mc-res-pi').innerHTML = formatter.format(monthlyPI);
document.getElementById('mc-res-tax').innerHTML = formatter.format(monthlyTax);
document.getElementById('mc-res-ins').innerHTML = formatter.format(monthlyIns);
document.getElementById('mc-res-total').innerHTML = formatter.format(totalMonthly);
resultsDiv.style.display = 'block';
}
Mortgage Payment Calculator
30 Years
20 Years
15 Years
10 Years
Please enter valid positive numbers for all fields.
Principal & Interest:
$0.00
Monthly Property Tax:
$0.00
Monthly Home Insurance:
$0.00
Total Monthly Payment:
$0.00
*Estimates only. Does not include HOA fees or PMI.
Understanding Your Mortgage Payment
Purchasing a home is likely the largest financial decision you will make. This Mortgage Payment Calculator helps you estimate your monthly housing costs by breaking down the key components: Principal, Interest, Taxes, and Insurance (often referred to as PITI).
Key Factors Affecting Your Payment
- Home Price & Down Payment: The difference between these two figures gives you your loan amount (Principal). A larger down payment reduces your principal and, consequently, your monthly interest obligations.
- Interest Rate: Even a fraction of a percentage point can significantly alter your monthly payment and the total interest paid over the life of the loan. Rates fluctuate based on the economy and your credit score.
- Loan Term: Most mortgages are 15 or 30 years. A 30-year term offers lower monthly payments but results in higher total interest costs. A 15-year term has higher payments but builds equity faster.
- Property Taxes & Insurance: These are often bundled into your monthly payment through an escrow account. These costs vary by location and property value.
What is Not Included?
While this calculator provides a robust estimate of PITI, remember to budget for other potential costs:
- Private Mortgage Insurance (PMI): Usually required if your down payment is less than 20%.
- HOA Fees: If buying a condo or in a planned community, these fees are paid separately.
- Maintenance: It is generally recommended to budget 1% of the home's value annually for repairs.
How to Lower Your Mortgage Payment
If the calculated total is higher than your budget allows, consider improving your credit score to secure a lower rate, saving for a larger down payment to avoid PMI, or looking for properties in areas with lower property taxes.