Mortgage Loan Calculator
:root {
–primary-blue: #004a99;
–success-green: #28a745;
–light-background: #f8f9fa;
–border-color: #dee2e6;
–text-color: #333;
–label-color: #495057;
}
body {
font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
line-height: 1.6;
color: var(–text-color);
background-color: var(–light-background);
margin: 0;
padding: 20px;
display: flex;
justify-content: center;
align-items: flex-start;
min-height: 100vh;
}
.loan-calc-container {
background-color: #ffffff;
padding: 30px;
border-radius: 8px;
box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
max-width: 700px;
width: 100%;
border: 1px solid var(–border-color);
}
h1, h2 {
color: var(–primary-blue);
text-align: center;
margin-bottom: 20px;
font-weight: 600;
}
.input-section, .result-section {
margin-bottom: 30px;
padding: 20px;
background-color: var(–light-background);
border-radius: 5px;
border: 1px solid var(–border-color);
}
.input-group {
margin-bottom: 15px;
display: flex;
align-items: center;
flex-wrap: wrap;
}
.input-group label {
display: block;
margin-bottom: 8px;
color: var(–label-color);
font-weight: 500;
flex: 1 1 150px; /* Allows label to take space but not overflow */
padding-right: 10px;
}
.input-group input[type="number"],
.input-group input[type="text"] {
padding: 10px 12px;
border: 1px solid var(–border-color);
border-radius: 4px;
font-size: 1rem;
flex: 2 1 200px; /* Allows input to take more space */
box-sizing: border-box; /* Include padding and border in element's total width/height */
}
.input-group span.unit {
padding-left: 10px;
color: var(–label-color);
font-weight: 500;
flex-shrink: 0; /* Prevent unit from shrinking */
}
button {
background-color: var(–primary-blue);
color: white;
padding: 12px 25px;
border: none;
border-radius: 5px;
font-size: 1.1rem;
cursor: pointer;
transition: background-color 0.3s ease;
width: 100%;
font-weight: 500;
box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}
button:hover {
background-color: #003366;
}
#result {
background-color: var(–success-green);
color: white;
padding: 20px;
text-align: center;
border-radius: 5px;
font-size: 1.5rem;
font-weight: bold;
margin-top: 20px;
box-shadow: 0 2px 10px rgba(40, 167, 69, 0.3);
}
#result span {
font-size: 1.2rem;
display: block;
margin-top: 5px;
}
.article-section {
margin-top: 40px;
padding: 25px;
background-color: #ffffff;
border-radius: 8px;
box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
border: 1px solid var(–border-color);
}
.article-section h2 {
margin-bottom: 15px;
color: var(–primary-blue);
}
.article-section h3 {
margin-top: 20px;
margin-bottom: 10px;
color: var(–primary-blue);
}
.article-section p, .article-section li {
margin-bottom: 15px;
color: var(–text-color);
}
.article-section ul {
padding-left: 20px;
}
.article-section li {
margin-bottom: 10px;
}
/* Responsive adjustments */
@media (max-width: 600px) {
.input-group {
flex-direction: column;
align-items: stretch;
}
.input-group label, .input-group input[type="number"], .input-group input[type="text"], .input-group span.unit {
flex: none;
width: 100%;
margin-bottom: 10px;
}
.input-group span.unit {
text-align: right; /* Align units to the right on smaller screens */
}
#result {
font-size: 1.3rem;
}
}
Mortgage Loan Calculator
Your Estimated Monthly Payment
—
Understanding Your Mortgage Payment
A mortgage is a significant financial commitment, and understanding how your monthly payment is calculated is crucial for making informed decisions. This calculator helps you estimate your principal and interest payment based on the loan amount, interest rate, and loan term.
The Mortgage Payment Formula
The standard formula for calculating a fixed-rate mortgage's monthly payment (P&I – Principal and Interest) is:
M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1]
Where:
M = Your total monthly mortgage payment (Principal & Interest)P = The principal loan amount (the amount you borrow)i = Your monthly interest rate (annual interest rate divided by 12)n = The total number of payments over the loan's lifetime (loan term in years multiplied by 12)
How the Calculator Works
Our calculator takes the values you input for:
- Loan Amount: The total sum you are borrowing for the property.
- Annual Interest Rate: The yearly interest rate charged by the lender. This is converted to a monthly rate (divided by 12) for the calculation.
- Loan Term (Years): The total duration of the loan, typically 15, 20, or 30 years. This is converted to the total number of monthly payments (multiplied by 12).
It then applies the formula above to estimate your P&I payment. Please note that this calculation typically excludes other costs associated with homeownership, such as property taxes, homeowner's insurance, and private mortgage insurance (PMI), which are often included in your actual total monthly housing payment (escrow).
Why Use a Mortgage Calculator?
- Budgeting: Helps you determine how much house you can afford by understanding the monthly financial obligation.
- Comparing Loans: Allows you to easily compare offers from different lenders by inputting various interest rates and terms.
- Financial Planning: Provides a clear estimate for your long-term financial planning.
- Understanding Affordability: Get a quick sense of the monthly cost for different loan scenarios.
Important Considerations:
- The results are estimates. Actual loan payments may vary due to lender fees, specific loan product terms, and changes in interest rates (for adjustable-rate mortgages).
- This calculator focuses on the Principal and Interest (P&I) portion of your mortgage payment. Your total monthly payment will likely be higher when including property taxes, homeowner's insurance, and potential PMI.
- It's always recommended to speak with a mortgage professional or financial advisor for personalized advice.
function calculateMortgage() {
var loanAmount = parseFloat(document.getElementById("loanAmount").value);
var interestRate = parseFloat(document.getElementById("interestRate").value);
var loanTerm = parseFloat(document.getElementById("loanTerm").value);
var resultElement = document.getElementById("result");
resultElement.innerHTML = "–"; // Reset result
// Validate inputs
if (isNaN(loanAmount) || isNaN(interestRate) || isNaN(loanTerm) || loanAmount <= 0 || interestRate < 0 || loanTerm <= 0) {
resultElement.innerHTML = "Please enter valid numbers.";
return;
}
// Calculate monthly interest rate
var monthlyInterestRate = interestRate / 100 / 12;
// Calculate the number of payments
var numberOfPayments = loanTerm * 12;
// Calculate monthly mortgage payment using the formula
// M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1]
var numerator = monthlyInterestRate * Math.pow((1 + monthlyInterestRate), numberOfPayments);
var denominator = Math.pow((1 + monthlyInterestRate), numberOfPayments) – 1;
var monthlyPayment = 0;
if (denominator !== 0) {
monthlyPayment = loanAmount * (numerator / denominator);
} else if (monthlyInterestRate === 0) {
// Handle zero interest rate case (simple division)
monthlyPayment = loanAmount / numberOfPayments;
} else {
resultElement.innerHTML = "Calculation error.";
return;
}
// Display the result, formatted to two decimal places
resultElement.innerHTML = "$" + monthlyPayment.toFixed(2) + "
Principal & Interest";
}