.calc-header { background: #0056b3; color: white; padding: 20px; text-align: center; }
.calc-header h2 { margin: 0; font-size: 24px; }
.calc-body { padding: 30px; }
.input-group { margin-bottom: 20px; }
.input-group label { display: block; font-weight: 600; margin-bottom: 8px; color: #333; }
.input-group input { width: 100%; padding: 12px; border: 1px solid #ccc; border-radius: 4px; font-size: 16px; box-sizing: border-box; }
.input-group input:focus { border-color: #0056b3; outline: none; }
.calc-btn { width: 100%; background: #28a745; color: white; border: none; padding: 15px; font-size: 18px; font-weight: bold; border-radius: 4px; cursor: pointer; transition: background 0.3s; }
.calc-btn:hover { background: #218838; }
.results-box { background: #f8f9fa; padding: 20px; border-radius: 4px; margin-top: 25px; border-left: 5px solid #0056b3; display: none; }
.result-row { display: flex; justify-content: space-between; margin-bottom: 10px; font-size: 16px; }
.result-row.main-result { font-weight: bold; font-size: 22px; color: #0056b3; border-top: 1px solid #ddd; padding-top: 10px; margin-top: 10px; }
.seo-content { padding: 30px; background: #fafafa; border-top: 1px solid #eee; line-height: 1.6; color: #444; }
.seo-content h3 { color: #2c3e50; margin-top: 0; }
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
@media (max-width: 600px) { .grid-2 { grid-template-columns: 1fr; } }
function calculateAffordability() {
// 1. Get Input Values
var annualIncome = parseFloat(document.getElementById("grossIncome").value);
var monthlyDebts = parseFloat(document.getElementById("monthlyDebts").value);
var downPayment = parseFloat(document.getElementById("downPayment").value);
var interestRate = parseFloat(document.getElementById("interestRate").value);
var loanTerm = parseFloat(document.getElementById("loanTerm").value);
// 2. Validation
if (isNaN(annualIncome) || annualIncome <= 0) {
alert("Please enter a valid Annual Gross Income.");
return;
}
if (isNaN(monthlyDebts) || monthlyDebts < 0) {
monthlyDebts = 0;
}
if (isNaN(downPayment) || downPayment < 0) {
downPayment = 0;
}
if (isNaN(interestRate) || interestRate <= 0) {
alert("Please enter a valid Interest Rate.");
return;
}
if (isNaN(loanTerm) || loanTerm <= 0) {
alert("Please enter a valid Loan Term.");
return;
}
// 3. Calculation Logic
var monthlyIncome = annualIncome / 12;
// Calculate Max Payment based on Front-End Ratio (28%)
var maxFrontEnd = monthlyIncome * 0.28;
// Calculate Max Payment based on Back-End Ratio (36%)
// Max Housing Payment = (Income * 0.36) – Existing Debts
var maxBackEnd = (monthlyIncome * 0.36) – monthlyDebts;
// The lender will typically use the LOWER of the two
var maxMonthlyPayment = Math.min(maxFrontEnd, maxBackEnd);
// If debts are too high, max payment might be negative or zero
if (maxMonthlyPayment <= 0) {
document.getElementById("resultsArea").style.display = "block";
document.getElementById("displayMaxPayment").innerText = "$0.00";
document.getElementById("displayLoanAmount").innerText = "$0.00";
document.getElementById("displayHomePrice").innerText = "Not Eligible";
return;
}
// Calculate Max Loan Amount based on Max Monthly Payment
// Formula: PV = PMT * (1 – (1 + r)^-n) / r
var r = (interestRate / 100) / 12; // Monthly interest rate
var n = loanTerm * 12; // Total number of payments
// NOTE: We assume the maxMonthlyPayment includes Taxes and Insurance.
// To be safe, we estimate P&I is roughly 80% of the total PITI for calculation purposes,
// or we calculate the raw loan power and subtract a buffer.
// For this specific logic, we will assume the calculated max payment is strictly for P&I
// to give a "Maximum theoretical" or adjust slightly.
// Let's adjust: reduce maxPayment by 15% to account for Taxes/Ins estimated.
var paymentForPrincipalInterest = maxMonthlyPayment * 0.85;
var maxLoanAmount = (paymentForPrincipalInterest * (1 – Math.pow((1 + r), -n))) / r;
var maxHomePrice = maxLoanAmount + downPayment;
// 4. Update UI
document.getElementById("resultsArea").style.display = "block";
// Format numbers as Currency
var formatter = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
minimumFractionDigits: 0,
maximumFractionDigits: 0,
});
document.getElementById("displayMaxPayment").innerText = formatter.format(maxMonthlyPayment) + " /mo";
document.getElementById("displayLoanAmount").innerText = formatter.format(maxLoanAmount);
document.getElementById("displayHomePrice").innerText = formatter.format(maxHomePrice);
}
House Affordability Calculator
Maximum Monthly Payment:
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Max Loan Amount:
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Maximum Home Price:
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How Much House Can You Really Afford?
Determining your budget is the first critical step in the home buying process. This House Affordability Calculator uses the standard debt-to-income (DTI) ratios preferred by mortgage lenders to give you a realistic estimate of your purchasing power.
Understanding the 28/36 Rule
Most financial experts and lenders utilize the "28/36 rule" to determine affordability:
- Front-End Ratio (28%): Your monthly housing costs (principal, interest, taxes, and insurance) should not exceed 28% of your gross monthly income.
- Back-End Ratio (36%): Your total monthly debt payments (housing costs + credit cards, car loans, student loans, etc.) should not exceed 36% of your gross monthly income.
Key Factors Affecting Your Budget
Several variables impact how much house you can buy. A higher Down Payment reduces the loan amount needed, directly increasing your price range. Conversely, high Monthly Debts reduce your back-end ratio, lowering the amount a bank will lend you. Finally, your Interest Rate plays a massive role; a 1% increase in rates can significantly reduce your buying power by increasing monthly payments.
Note: This calculator provides an estimate based on standard lending criteria. Always consult with a qualified mortgage professional for pre-approval.