Mortgage Payment Calculator
.mp-calculator-widget {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
max-width: 800px;
margin: 0 auto;
padding: 20px;
background: #ffffff;
border: 1px solid #e0e0e0;
border-radius: 8px;
box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}
.mp-calculator-title {
text-align: center;
color: #2c3e50;
margin-bottom: 25px;
font-size: 28px;
}
.mp-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 20px;
}
@media (max-width: 600px) {
.mp-grid {
grid-template-columns: 1fr;
}
}
.mp-input-group {
margin-bottom: 15px;
}
.mp-input-group label {
display: block;
margin-bottom: 5px;
font-weight: 600;
color: #4a5568;
}
.mp-input-group input {
width: 100%;
padding: 10px;
border: 1px solid #cbd5e0;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
transition: border-color 0.2s;
}
.mp-input-group input:focus {
border-color: #3182ce;
outline: none;
box-shadow: 0 0 0 3px rgba(49, 130, 206, 0.1);
}
.mp-btn-container {
text-align: center;
margin-top: 20px;
}
.mp-calculate-btn {
background-color: #3182ce;
color: white;
border: none;
padding: 12px 30px;
font-size: 18px;
font-weight: bold;
border-radius: 5px;
cursor: pointer;
transition: background-color 0.2s;
}
.mp-calculate-btn:hover {
background-color: #2c5282;
}
.mp-results-section {
margin-top: 30px;
padding: 20px;
background-color: #f7fafc;
border-radius: 6px;
border: 1px solid #edf2f7;
display: none;
}
.mp-result-row {
display: flex;
justify-content: space-between;
padding: 10px 0;
border-bottom: 1px solid #e2e8f0;
}
.mp-result-row:last-child {
border-bottom: none;
}
.mp-result-label {
color: #718096;
}
.mp-result-value {
font-weight: bold;
color: #2d3748;
font-size: 18px;
}
.mp-total-monthly {
background-color: #ebf8ff;
padding: 15px;
border-radius: 5px;
margin-top: 15px;
text-align: center;
}
.mp-total-label {
display: block;
color: #2b6cb0;
font-weight: 600;
margin-bottom: 5px;
}
.mp-total-value {
font-size: 32px;
color: #2c5282;
font-weight: 800;
}
.mp-content-article {
max-width: 800px;
margin: 40px auto;
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
line-height: 1.6;
color: #333;
}
.mp-content-article h2 {
color: #2c3e50;
margin-top: 30px;
}
.mp-content-article h3 {
color: #34495e;
margin-top: 25px;
}
.mp-content-article p {
margin-bottom: 15px;
}
.mp-content-article ul {
margin-bottom: 20px;
padding-left: 20px;
}
.mp-content-article li {
margin-bottom: 8px;
}
.error-msg {
color: #e53e3e;
text-align: center;
margin-top: 10px;
display: none;
}
Understanding Your Mortgage Payments
Purchasing a home is one of the most significant financial decisions you will make. Using a Mortgage Payment Calculator is essential to understand exactly how much house you can afford. This tool breaks down your monthly obligations into the core components of PITI: Principal, Interest, Taxes, and Insurance.
What Factors Influence Your Monthly Payment?
Your monthly mortgage payment is not just about repaying the loan. It consists of several distinct parts:
- Principal: The portion of the payment that reduces the loan balance.
- Interest: The cost of borrowing money, determined by your interest rate.
- Property Taxes: Fees paid to your local government, usually collected by the lender in escrow and divided into monthly installments.
- Homeowners Insurance: Protection for your property against damage, also typically paid via escrow.
How the Calculation Works
This calculator uses the standard amortization formula to determine the principal and interest payment:
M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
Where M is the monthly payment, P is the principal loan amount, i is the monthly interest rate, and n is the number of months required to repay the loan.
Tips for Lowering Your Payment
If the estimated payment is higher than your budget allows, consider these strategies:
- Increase your Down Payment: Putting more money down reduces the principal loan amount and can eliminate Private Mortgage Insurance (PMI).
- Improve your Credit Score: A higher score can qualify you for a lower interest rate, significantly reducing costs over time.
- Extend the Loan Term: Choosing a 30-year term over a 15-year term lowers monthly payments, though you will pay more in total interest.
function calculateMortgage() {
var homePrice = parseFloat(document.getElementById('mp-home-price').value);
var downPayment = parseFloat(document.getElementById('mp-down-payment').value);
var interestRate = parseFloat(document.getElementById('mp-interest-rate').value);
var loanTermYears = parseFloat(document.getElementById('mp-loan-term').value);
var annualTax = parseFloat(document.getElementById('mp-property-tax').value);
var annualInsurance = parseFloat(document.getElementById('mp-insurance').value);
var errorMsg = document.getElementById('mp-error');
var resultsDiv = document.getElementById('mp-results');
// Validation
if (isNaN(homePrice) || isNaN(downPayment) || isNaN(interestRate) || isNaN(loanTermYears) ||
homePrice <= 0 || interestRate < 0 || loanTermYears <= 0) {
errorMsg.style.display = 'block';
resultsDiv.style.display = 'none';
return;
}
// Handle optional fields as 0 if empty/NaN
if (isNaN(annualTax)) annualTax = 0;
if (isNaN(annualInsurance)) annualInsurance = 0;
errorMsg.style.display = 'none';
// Core Calculation Logic
var principal = homePrice – downPayment;
if (principal = Home Price
document.getElementById('mp-final-monthly').innerText = "$0.00";
document.getElementById('mp-pi-val').innerText = "$0.00";
document.getElementById('mp-tax-val').innerText = "$" + (annualTax / 12).toFixed(2);
document.getElementById('mp-ins-val').innerText = "$" + (annualInsurance / 12).toFixed(2);
document.getElementById('mp-loan-amount').innerText = "$0.00";
document.getElementById('mp-total-interest').innerText = "$0.00";
resultsDiv.style.display = 'block';
return;
}
var monthlyInterestRate = (interestRate / 100) / 12;
var numberOfPayments = loanTermYears * 12;
// Amortization Formula
// M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
var monthlyPI = 0;
if (monthlyInterestRate === 0) {
monthlyPI = principal / numberOfPayments;
} else {
monthlyPI = principal * ( (monthlyInterestRate * Math.pow(1 + monthlyInterestRate, numberOfPayments)) / (Math.pow(1 + monthlyInterestRate, numberOfPayments) – 1) );
}
var monthlyTax = annualTax / 12;
var monthlyInsurance = annualInsurance / 12;
var totalMonthlyPayment = monthlyPI + monthlyTax + monthlyInsurance;
var totalInterest = (monthlyPI * numberOfPayments) – principal;
// Formatting currency
var formatMoney = function(num) {
return "$" + num.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2});
};
// Updating UI
document.getElementById('mp-final-monthly').innerText = formatMoney(totalMonthlyPayment);
document.getElementById('mp-pi-val').innerText = formatMoney(monthlyPI);
document.getElementById('mp-tax-val').innerText = formatMoney(monthlyTax);
document.getElementById('mp-ins-val').innerText = formatMoney(monthlyInsurance);
document.getElementById('mp-loan-amount').innerText = formatMoney(principal);
document.getElementById('mp-total-interest').innerText = formatMoney(totalInterest);
resultsDiv.style.display = 'block';
}