.mc-container {
background: #f9f9f9;
border: 1px solid #e0e0e0;
border-radius: 8px;
padding: 25px;
box-shadow: 0 4px 6px rgba(0,0,0,0.05);
margin-bottom: 40px;
}
.mc-header {
text-align: center;
margin-bottom: 25px;
color: #2c3e50;
}
.mc-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 20px;
}
@media (max-width: 600px) {
.mc-grid {
grid-template-columns: 1fr;
}
}
.mc-input-group {
margin-bottom: 15px;
}
.mc-input-group label {
display: block;
margin-bottom: 5px;
font-weight: 600;
color: #555;
font-size: 0.9em;
}
.mc-input-group input {
width: 100%;
padding: 10px;
border: 1px solid #ccc;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
}
.mc-input-group input:focus {
border-color: #3498db;
outline: none;
}
.mc-btn {
width: 100%;
padding: 15px;
background-color: #2980b9;
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: #2471a3;
}
.mc-result {
margin-top: 25px;
padding: 20px;
background-color: #fff;
border: 1px solid #ddd;
border-radius: 4px;
display: none;
}
.mc-result h3 {
margin-top: 0;
color: #2c3e50;
border-bottom: 2px solid #3498db;
padding-bottom: 10px;
}
.mc-result-row {
display: flex;
justify-content: space-between;
margin-bottom: 10px;
padding-bottom: 10px;
border-bottom: 1px dotted #eee;
}
.mc-result-row:last-child {
border-bottom: none;
}
.mc-highlight {
font-size: 1.5em;
color: #27ae60;
font-weight: bold;
}
.mc-error {
color: #c0392b;
text-align: center;
margin-top: 10px;
display: none;
}
/* Article Styles */
.mc-article {
line-height: 1.6;
color: #333;
}
.mc-article h2 {
color: #2c3e50;
margin-top: 30px;
}
.mc-article p {
margin-bottom: 15px;
}
.mc-article ul {
margin-bottom: 20px;
padding-left: 20px;
}
.mc-article li {
margin-bottom: 8px;
}
Understanding Your Mortgage Calculation
Buying a home is one of the largest financial decisions most people will make in their lifetime. Our Mortgage Payment Calculator is designed to provide clarity on what your financial commitment will look like on a monthly basis. By adjusting the home price, down payment, interest rate, and loan term, you can see how different scenarios affect your bottom line.
How the Mortgage Formula Works
The standard formula used to calculate a fixed-rate mortgage monthly payment is:
M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
- M = Total monthly payment
- P = The principal loan amount (Home Price minus Down Payment)
- i = Monthly interest rate (Annual Rate divided by 12)
- n = Number of payments over the loan's lifetime (Years multiplied by 12)
Key Factors Affecting Your Payment
Several variables can significantly impact your monthly housing costs:
1. Down Payment
The more money you put down upfront, the less you need to borrow. A larger down payment reduces your principal loan amount, which lowers your monthly payment and the total interest paid over the life of the loan. Additionally, putting down at least 20% often helps you avoid Private Mortgage Insurance (PMI).
2. Interest Rate
Even a fraction of a percentage point can change your monthly payment by hundreds of dollars. Interest rates fluctuate based on the economy and your personal credit score. Securing a lower rate is one of the most effective ways to save money long-term.
3. Loan Term
The most common loan terms are 15 and 30 years. A 30-year mortgage offers lower monthly payments but results in paying significantly more interest over time. A 15-year mortgage has higher monthly payments but builds equity faster and saves on total interest costs.
Using This Calculator for Budgeting
When planning your budget, remember that this calculator estimates the Principal and Interest (P&I). However, your actual monthly housing expense will likely include other costs known as PITI:
- Principal: The money that goes towards paying down the loan balance.
- Interest: The cost of borrowing the money.
- Taxes: Property taxes charged by your local government.
- Insurance: Homeowners insurance to protect your property.
Use the "Monthly Principal & Interest" figure generated above as a baseline, and be sure to add estimates for taxes and insurance to understand your true affordability.
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 loanTerm = parseFloat(document.getElementById('mc-loan-term').value);
// Error Handling elements
var errorDiv = document.getElementById('mc-error');
var resultDiv = document.getElementById('mc-result');
// Basic Validation
if (isNaN(homePrice) || isNaN(downPayment) || isNaN(interestRate) || isNaN(loanTerm) ||
homePrice <= 0 || interestRate < 0 || loanTerm = homePrice) {
errorDiv.innerHTML = "Down payment cannot be greater than or equal to the home price.";
errorDiv.style.display = 'block';
resultDiv.style.display = 'none';
return;
} else {
errorDiv.style.display = 'none';
}
// Calculations
var principal = homePrice – downPayment;
var monthlyRate = (interestRate / 100) / 12;
var numberOfPayments = loanTerm * 12;
var monthlyPayment = 0;
// Handle 0% interest case
if (interestRate === 0) {
monthlyPayment = principal / numberOfPayments;
} else {
// Formula: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
var mathPower = Math.pow(1 + monthlyRate, numberOfPayments);
monthlyPayment = principal * ((monthlyRate * mathPower) / (mathPower – 1));
}
var totalPayment = monthlyPayment * numberOfPayments;
var totalInterest = totalPayment – principal;
// Calculate Payoff Date
var today = new Date();
var payoffDate = new Date(today.setMonth(today.getMonth() + numberOfPayments));
var dateOptions = { month: 'long', year: 'numeric' };
var payoffString = payoffDate.toLocaleDateString('en-US', dateOptions);
// Formatting Function
function formatMoney(num) {
return '$' + num.toFixed(2).replace(/\d(?=(\d{3})+\.)/g, '$&,');
}
// Display Results
document.getElementById('mc-monthly-val').innerText = formatMoney(monthlyPayment);
document.getElementById('mc-total-loan').innerText = formatMoney(principal);
document.getElementById('mc-total-interest').innerText = formatMoney(totalInterest);
document.getElementById('mc-total-cost').innerText = formatMoney(totalPayment);
document.getElementById('mc-payoff-date').innerText = payoffString;
resultDiv.style.display = 'block';
}