#mortgage-calculator-wrapper h2 {
text-align: center;
color: #333;
margin-bottom: 25px;
}
.mc-row {
display: flex;
flex-wrap: wrap;
gap: 20px;
margin-bottom: 20px;
}
.mc-col {
flex: 1;
min-width: 250px;
}
.mc-input-group {
margin-bottom: 15px;
}
.mc-input-group label {
display: block;
margin-bottom: 5px;
font-weight: 600;
color: #555;
}
.mc-input-group input {
width: 100%;
padding: 10px;
border: 1px solid #ccc;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
}
.mc-btn {
width: 100%;
padding: 15px;
background-color: #2c3e50;
color: #fff;
border: none;
border-radius: 5px;
font-size: 18px;
font-weight: bold;
cursor: pointer;
transition: background-color 0.3s;
}
.mc-btn:hover {
background-color: #34495e;
}
#mc-results {
background-color: #fff;
padding: 20px;
border-radius: 6px;
border-left: 5px solid #27ae60;
margin-top: 25px;
display: none;
box-shadow: 0 2px 5px rgba(0,0,0,0.05);
}
.mc-result-row {
display: flex;
justify-content: space-between;
padding: 10px 0;
border-bottom: 1px solid #eee;
}
.mc-result-row:last-child {
border-bottom: none;
}
.mc-result-label {
color: #666;
}
.mc-result-value {
font-weight: bold;
color: #333;
}
.mc-total {
font-size: 1.2em;
color: #27ae60;
}
.mc-article {
margin-top: 40px;
line-height: 1.6;
color: #444;
}
.mc-article h3 {
color: #2c3e50;
margin-top: 25px;
}
.mc-article ul {
padding-left: 20px;
}
.mc-article li {
margin-bottom: 10px;
}
function calculateMortgage() {
// Get Input Values
var homePrice = parseFloat(document.getElementById('mcHomePrice').value);
var downPayment = parseFloat(document.getElementById('mcDownPayment').value);
var interestRate = parseFloat(document.getElementById('mcInterestRate').value);
var loanTerm = parseFloat(document.getElementById('mcLoanTerm').value);
var annualTax = parseFloat(document.getElementById('mcPropertyTax').value);
var annualInsurance = parseFloat(document.getElementById('mcInsurance').value);
// Validation
if (isNaN(homePrice) || isNaN(downPayment) || isNaN(interestRate) || isNaN(loanTerm)) {
alert("Please enter valid numbers for all fields.");
return;
}
// Calculation Logic
var loanAmount = homePrice – downPayment;
// Handle edge case where loan amount is negative or zero
if (loanAmount <= 0) {
alert("Down payment cannot be greater than or equal to the home price.");
return;
}
var monthlyInterestRate = (interestRate / 100) / 12;
var totalPayments = loanTerm * 12;
// Mortgage Formula: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
var monthlyPrincipalInterest = 0;
if (interestRate === 0) {
monthlyPrincipalInterest = loanAmount / totalPayments;
} else {
var mathPower = Math.pow(1 + monthlyInterestRate, totalPayments);
monthlyPrincipalInterest = loanAmount * (monthlyInterestRate * mathPower) / (mathPower – 1);
}
// Tax and Insurance Monthly
var monthlyTax = isNaN(annualTax) ? 0 : annualTax / 12;
var monthlyInsurance = isNaN(annualInsurance) ? 0 : annualInsurance / 12;
var totalMonthlyPayment = monthlyPrincipalInterest + monthlyTax + monthlyInsurance;
var totalTotalInterest = (monthlyPrincipalInterest * totalPayments) – loanAmount;
// Formatting Function
function formatCurrency(num) {
return "$" + num.toFixed(2).replace(/\d(?=(\d{3})+\.)/g, '$&,');
}
// Update DOM
document.getElementById('resPrincipalInterest').innerHTML = formatCurrency(monthlyPrincipalInterest);
document.getElementById('resTax').innerHTML = formatCurrency(monthlyTax);
document.getElementById('resInsurance').innerHTML = formatCurrency(monthlyInsurance);
document.getElementById('resTotal').innerHTML = formatCurrency(totalMonthlyPayment);
document.getElementById('resLoanAmount').innerHTML = formatCurrency(loanAmount);
document.getElementById('resTotalInterest').innerHTML = formatCurrency(totalTotalInterest);
// Show Results
document.getElementById('mc-results').style.display = 'block';
}
Mortgage Payment Calculator
Monthly Payment Breakdown
Principal & Interest:
$0.00
Property Tax (Monthly):
$0.00
Home Insurance (Monthly):
$0.00
TOTAL MONTHLY PAYMENT:
$0.00
Total Loan Amount: $0
Total Interest Over Loan Life: $0
Understanding Your Mortgage Payment
Buying a home is one of the largest financial decisions you will make. This Mortgage Calculator helps you estimate your monthly payments so you can budget effectively. Understanding the components of your mortgage payment is crucial for determining affordability.
Components of a Mortgage Payment
Your monthly payment is typically comprised of four main parts, often referred to as PITI:
- Principal: The money that goes towards paying down the loan balance.
- Interest: The cost of borrowing money, paid to the lender.
- Taxes: Property taxes charged by your local government, often held in escrow by the lender.
- Insurance: Homeowners insurance to protect your property against damage, also frequently paid via escrow.
How Interest Rates Affect Affordability
Even a small difference in interest rates can significantly impact your monthly payment and the total cost of the loan. For example, on a $300,000 loan, a 1% increase in interest rate can increase your monthly payment by hundreds of dollars and your total interest paid by tens of thousands over 30 years.
Loan Term: 15 vs. 30 Years
The term of your loan determines how long you have to repay it. A 30-year mortgage usually offers lower monthly payments but results in paying more interest over the life of the loan. A 15-year mortgage has higher monthly payments, but you build equity faster and pay significantly less in total interest.