/* Calculator Styles */
.mortgage-calc-wrapper {
max-width: 800px;
margin: 0 auto;
font-family: -apple-system, BlinkMacSystemFont, “Segoe UI”, Roboto, Helvetica, Arial, sans-serif;
border: 1px solid #e2e8f0;
border-radius: 8px;
background: #ffffff;
box-shadow: 0 4px 6px rgba(0,0,0,0.05);
padding: 20px;
}
.calc-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 20px;
}
@media (max-width: 600px) {
.calc-grid {
grid-template-columns: 1fr;
}
}
.input-group {
margin-bottom: 15px;
}
.input-group label {
display: block;
font-weight: 600;
margin-bottom: 5px;
color: #2d3748;
font-size: 0.95em;
}
.input-wrapper {
position: relative;
display: flex;
align-items: center;
}
.currency-symbol, .percent-symbol {
position: absolute;
color: #718096;
font-size: 0.9em;
}
.currency-symbol { left: 10px; }
.percent-symbol { right: 10px; }
.calc-input {
width: 100%;
padding: 10px 12px;
padding-left: 25px; /* space for $ */
border: 1px solid #cbd5e0;
border-radius: 6px;
font-size: 1em;
transition: border-color 0.2s;
}
.calc-input:focus {
border-color: #4299e1;
outline: none;
box-shadow: 0 0 0 3px rgba(66, 153, 225, 0.2);
}
.calc-input.has-percent {
padding-left: 12px;
padding-right: 25px;
}
.calc-btn {
grid-column: 1 / -1;
background-color: #2b6cb0;
color: white;
border: none;
padding: 15px;
font-size: 1.1em;
font-weight: bold;
border-radius: 6px;
cursor: pointer;
transition: background-color 0.2s;
margin-top: 10px;
}
.calc-btn:hover {
background-color: #2c5282;
}
.results-section {
grid-column: 1 / -1;
background-color: #f7fafc;
border-radius: 6px;
padding: 20px;
margin-top: 20px;
border: 1px solid #edf2f7;
display: none; /* Hidden until calculated */
}
.result-row {
display: flex;
justify-content: space-between;
margin-bottom: 10px;
padding-bottom: 10px;
border-bottom: 1px solid #e2e8f0;
}
.result-row:last-child {
border-bottom: none;
margin-bottom: 0;
padding-bottom: 0;
}
.result-label {
color: #4a5568;
}
.result-value {
font-weight: bold;
color: #2d3748;
}
.total-payment {
font-size: 1.4em;
color: #2b6cb0;
}
/* Article Styles */
.seo-content {
max-width: 800px;
margin: 40px auto;
font-family: -apple-system, BlinkMacSystemFont, “Segoe UI”, Roboto, sans-serif;
line-height: 1.6;
color: #2d3748;
}
.seo-content h2 {
color: #1a202c;
border-bottom: 2px solid #e2e8f0;
padding-bottom: 10px;
margin-top: 30px;
}
.seo-content p {
margin-bottom: 15px;
}
.seo-content ul {
margin-bottom: 20px;
padding-left: 20px;
}
.seo-content li {
margin-bottom: 8px;
}
%
$0.00
$0.00
$0.00
$0.00
$0.00
$0.00
How to Use This Mortgage Calculator
Understanding your potential monthly mortgage payment is the first critical step in the home buying process. This Advanced Mortgage Calculator helps you estimate not just your principal and interest, but also factors in property taxes and home insurance, giving you a realistic view of your “PITI” (Principal, Interest, Taxes, Insurance) payment.
Key Factors Affecting Your Mortgage Payment
When calculating your monthly obligation, consider these four main components:
- Principal: The portion of your payment that goes toward paying down the loan balance (Home Price minus Down Payment).
- Interest: The cost of borrowing money, determined by your interest rate. A lower rate can save you thousands over the life of the loan.
- Property Taxes: An annual tax levied by your local government, usually bundled into your monthly mortgage payment via an escrow account.
- Home Insurance: Protection for your property against damage, also typically paid monthly through escrow.
How Interest Rates Impact Affordability
Even a small fluctuation in interest rates can significantly affect your monthly payment. For example, on a $300,000 loan, the difference between a 6% and a 7% interest rate is roughly $200 per month. Use the calculator above to test different rate scenarios to see how they impact your budget.
Optimizing Your Down Payment
Putting 20% down is the standard to avoid Private Mortgage Insurance (PMI). If you put down less than 20%, your monthly payment will likely be higher due to PMI costs, which are not calculated here but should be considered if your down payment is low. Increasing your down payment reduces your principal loan amount and immediately lowers your monthly P&I obligation.
function calculateMortgage() {
// 1. Get Input Values
var homePrice = parseFloat(document.getElementById(“homePrice”).value);
var downPayment = parseFloat(document.getElementById(“downPayment”).value);
var loanTermYears = parseFloat(document.getElementById(“loanTerm”).value);
var annualInterestRate = parseFloat(document.getElementById(“interestRate”).value);
var propertyTaxAnnual = parseFloat(document.getElementById(“propertyTax”).value);
var homeInsuranceAnnual = parseFloat(document.getElementById(“homeInsurance”).value);
// 2. Validation
if (isNaN(homePrice) || isNaN(downPayment) || isNaN(loanTermYears) || isNaN(annualInterestRate)) {
alert(“Please enter valid numbers for all fields.”);
return;
}
if (homePrice <= 0 || loanTermYears = home price
if (principal < 0) principal = 0;
var monthlyInterestRate = (annualInterestRate / 100) / 12;
var totalPayments = loanTermYears * 12;
// Calculate Monthly Principal & Interest (PI)
var monthlyPI = 0;
if (annualInterestRate === 0) {
monthlyPI = principal / totalPayments;
} else {
// Formula: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1 ]
var x = Math.pow(1 + monthlyInterestRate, totalPayments);
monthlyPI = principal * ((monthlyInterestRate * x) / (x – 1));
}
// Calculate Monthly Tax and Insurance
var monthlyTax = isNaN(propertyTaxAnnual) ? 0 : propertyTaxAnnual / 12;
var monthlyInsurance = isNaN(homeInsuranceAnnual) ? 0 : homeInsuranceAnnual / 12;
var totalMonthlyPayment = monthlyPI + monthlyTax + monthlyInsurance;
// Calculate Total Interest Paid
var totalCostOfLoan = monthlyPI * totalPayments;
var totalInterest = totalCostOfLoan – principal;
// 4. Update UI
document.getElementById("resPrincipal").innerText = "$" + monthlyPI.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("resTax").innerText = "$" + monthlyTax.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("resIns").innerText = "$" + monthlyInsurance.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("resTotal").innerText = "$" + totalMonthlyPayment.toLocaleString('en-US', {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("resLoanAmount").innerText = "$" + principal.toLocaleString('en-US', {minimumFractionDigits: 0, maximumFractionDigits: 0});
document.getElementById("resTotalInterest").innerText = "$" + totalInterest.toLocaleString('en-US', {minimumFractionDigits: 0, maximumFractionDigits: 0});
// Show results
document.getElementById("resultsSection").style.display = "block";
}