/* Responsive Calculator Styles */
.affordability-calc-wrapper {
max-width: 800px;
margin: 20px auto;
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
border: 1px solid #e0e0e0;
border-radius: 8px;
background: #ffffff;
box-shadow: 0 4px 6px rgba(0,0,0,0.05);
overflow: hidden;
}
.calc-header {
background: #2c3e50;
color: #ffffff;
padding: 20px;
text-align: center;
}
.calc-header h2 {
margin: 0;
font-size: 24px;
}
.calc-body {
display: flex;
flex-wrap: wrap;
padding: 20px;
gap: 20px;
}
.calc-inputs {
flex: 1 1 300px;
padding-right: 10px;
}
.calc-results {
flex: 1 1 300px;
background: #f8f9fa;
padding: 20px;
border-radius: 8px;
display: flex;
flex-direction: column;
justify-content: center;
border: 1px solid #dee2e6;
}
.input-group {
margin-bottom: 15px;
}
.input-group label {
display: block;
margin-bottom: 5px;
font-weight: 600;
font-size: 14px;
color: #333;
}
.input-wrapper {
position: relative;
display: flex;
align-items: center;
}
.input-prefix, .input-suffix {
background: #e9ecef;
padding: 10px 12px;
border: 1px solid #ced4da;
color: #495057;
font-size: 14px;
}
.input-prefix { border-radius: 4px 0 0 4px; border-right: 0; }
.input-suffix { border-radius: 0 4px 4px 0; border-left: 0; }
.calc-input {
width: 100%;
padding: 10px;
border: 1px solid #ced4da;
font-size: 16px;
border-radius: 0;
}
.calc-input:focus {
outline: none;
border-color: #4dabf7;
box-shadow: 0 0 0 2px rgba(77, 171, 247, 0.2);
}
.calc-btn {
width: 100%;
padding: 14px;
background: #27ae60;
color: white;
border: none;
border-radius: 4px;
font-size: 16px;
font-weight: bold;
cursor: pointer;
transition: background 0.2s;
margin-top: 10px;
}
.calc-btn:hover {
background: #219150;
}
.result-row {
margin-bottom: 15px;
border-bottom: 1px solid #e9ecef;
padding-bottom: 10px;
}
.result-row:last-child {
border-bottom: none;
}
.result-label {
font-size: 14px;
color: #6c757d;
display: block;
}
.result-value {
font-size: 24px;
font-weight: 700;
color: #2c3e50;
display: block;
}
.result-value.large {
font-size: 32px;
color: #27ae60;
}
.dti-alert {
font-size: 13px;
margin-top: 5px;
padding: 8px;
border-radius: 4px;
}
.dti-good { background: #d4edda; color: #155724; }
.dti-warn { background: #fff3cd; color: #856404; }
.dti-bad { background: #f8d7da; color: #721c24; }
/* Article Content Styles */
.seo-content {
max-width: 800px;
margin: 40px auto;
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
line-height: 1.6;
color: #333;
}
.seo-content h2 { color: #2c3e50; margin-top: 30px; }
.seo-content h3 { color: #34495e; margin-top: 25px; }
.seo-content ul { padding-left: 20px; }
.seo-content li { margin-bottom: 10px; }
@media (max-width: 600px) {
.calc-body { flex-direction: column; }
.calc-inputs, .calc-results { width: 100%; padding-right: 0; }
}
Maximum Home Price
$0
Max Monthly Payment (P&I + Tax + Ins)
$0
Loan Amount
$0
Debt-to-Income (DTI) Analysis
Enter values to see analysis.
How Much House Can You Really Afford?
Determining your home buying power is the first critical step in the journey to homeownership. Unlike a simple mortgage payment calculator, our Mortgage Affordability Calculator uses the specific debt-to-income (DTI) guidelines that lenders actually use to approve loans.
How the Affordability Calculation Works
Lenders typically look at two primary ratios to decide how much they will lend you. This calculator adheres to the standard 28/36 rule, though some loan programs (like FHA) may allow for higher ratios:
- Front-End Ratio (28%): Your potential 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.
The calculator determines the maximum monthly payment allowed under both rules and uses the lower number to ensure you remain within safe financial limits.
Key Factors Affecting Your Purchasing Power
Several variables impact the final home price you can afford:
- Interest Rates: Even a 1% rise in interest rates can significantly reduce your buying power by increasing the cost of borrowing.
- Down Payment: A larger down payment reduces the loan amount needed, allowing you to buy a more expensive home for the same monthly payment.
- Existing Debt: High monthly obligations (like an expensive car lease) reduce your "Back-End" allowance, directly lowering the mortgage amount you can qualify for.
- Property Taxes: Buying in an area with high tax rates reduces the portion of your monthly payment that can go toward the loan principal.
Understanding the Results
If your results are lower than expected, consider paying down consumer debt before applying for a mortgage. Reducing a $400 monthly car payment can increase your mortgage qualification amount by roughly $50,000 to $70,000, depending on current interest rates.
function calculateAffordability() {
// 1. Get Input Values using var
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 loanTermYears = parseFloat(document.getElementById('loanTerm').value);
var propertyTaxRate = parseFloat(document.getElementById('propertyTaxRate').value);
var annualInsurance = parseFloat(document.getElementById('homeInsurance').value);
// 2. Validation
if (isNaN(annualIncome) || isNaN(interestRate) || isNaN(loanTermYears)) {
alert("Please enter valid numbers for Income, Interest Rate, and Term.");
return;
}
// Default 0 for optional fields if empty
if (isNaN(monthlyDebts)) monthlyDebts = 0;
if (isNaN(downPayment)) downPayment = 0;
if (isNaN(propertyTaxRate)) propertyTaxRate = 0;
if (isNaN(annualInsurance)) annualInsurance = 0;
// 3. Variables for Calculation
var monthlyGrossIncome = annualIncome / 12;
var monthlyRate = (interestRate / 100) / 12;
var numPayments = loanTermYears * 12;
// 4. Calculate Max Allowable Payment based on Ratios (28/36 Rule)
// Front-end: 28% of Income for Housing (PITI)
var maxHousingFront = monthlyGrossIncome * 0.28;
// Back-end: 36% of Income for Total Debts (Housing + Other Debts)
var maxTotalBack = monthlyGrossIncome * 0.36;
var maxHousingBack = maxTotalBack – monthlyDebts;
// The lender will use the LOWER of the two
var maxAllowedMonthlyPayment = Math.min(maxHousingFront, maxHousingBack);
// If debts are too high, maxHousingBack could be negative
if (maxAllowedMonthlyPayment Let's call the amortization factor 'A'
// So: MaxPayment = (Loan * A) + ((Loan + Down) * MonthlyTaxRate) + MonthlyIns
// MaxPayment = (Loan * A) + (Loan * MonthlyTaxRate) + (Down * MonthlyTaxRate) + MonthlyIns
// MaxPayment – (Down * MonthlyTaxRate) – MonthlyIns = Loan * (A + MonthlyTaxRate)
// Loan = (MaxPayment – (Down * MonthlyTaxRate) – MonthlyIns) / (A + MonthlyTaxRate)
var monthlyTaxRateDecimal = (propertyTaxRate / 100) / 12;
var monthlyInsuranceCost = annualInsurance / 12;
// Amortization Factor 'A'
var amortFactor = 0;
if (monthlyRate === 0) {
amortFactor = 1 / numPayments;
} else {
amortFactor = (monthlyRate * Math.pow(1 + monthlyRate, numPayments)) / (Math.pow(1 + monthlyRate, numPayments) – 1);
}
var numerator = maxAllowedMonthlyPayment – (downPayment * monthlyTaxRateDecimal) – monthlyInsuranceCost;
var denominator = amortFactor + monthlyTaxRateDecimal;
var maxLoanAmount = 0;
if (denominator !== 0) {
maxLoanAmount = numerator / denominator;
}
if (maxLoanAmount < 0) maxLoanAmount = 0;
var maxHomePrice = maxLoanAmount + downPayment;
// Recalculate actual P&I and Total Payment based on this Home Price to be precise for display
var finalLoanAmount = maxHomePrice – downPayment;
var finalPI = finalLoanAmount * amortFactor;
var finalTax = maxHomePrice * monthlyTaxRateDecimal;
var finalTotalMonthly = finalPI + finalTax + monthlyInsuranceCost;
// 6. Display Results
document.getElementById('resultHomePrice').innerText = formatCurrency(maxHomePrice);
document.getElementById('resultLoanAmount').innerText = formatCurrency(finalLoanAmount);
document.getElementById('resultMonthlyPayment').innerText = formatCurrency(finalTotalMonthly);
// 7. DTI Analysis Logic
var dtiElement = document.getElementById('dtiAnalysis');
var actualFrontEnd = (finalTotalMonthly / monthlyGrossIncome) * 100;
var actualBackEnd = ((finalTotalMonthly + monthlyDebts) / monthlyGrossIncome) * 100;
var dtiText = "
Front-End: " + actualFrontEnd.toFixed(1) + "% |
Back-End: " + actualBackEnd.toFixed(1) + "%";
// Logic for limiting factor
var limitMsg = "";
if (maxHousingBack < maxHousingFront) {
limitMsg = "Your buying power is limited by your
monthly debts.";
dtiElement.className = "dti-alert dti-warn";
} else {
limitMsg = "Your buying power is limited by
income (Front-end ratio).";
dtiElement.className = "dti-alert dti-good";
}
if (maxLoanAmount <= 0) {
dtiElement.innerHTML = "Debts are too high relative to income to qualify.";
dtiElement.className = "dti-alert dti-bad";
} else {
dtiElement.innerHTML = dtiText + limitMsg;
}
}
function formatCurrency(num) {
return "$" + num.toLocaleString('en-US', {minimumFractionDigits: 0, maximumFractionDigits: 0});
}
// Initial calculation on load for demo values
window.onload = function() {
// Optional: Auto calculate on load
// calculateAffordability();
};