.calculator-container-wrapper {
max-width: 800px;
margin: 0 auto;
font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
color: #333;
line-height: 1.6;
}
.calc-box {
background: #f8f9fa;
border: 1px solid #e9ecef;
border-radius: 8px;
padding: 30px;
box-shadow: 0 4px 6px rgba(0,0,0,0.05);
margin-bottom: 40px;
}
.calc-title {
text-align: center;
color: #2c3e50;
margin-bottom: 25px;
font-size: 28px;
font-weight: 700;
}
.form-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 20px;
}
@media (max-width: 600px) {
.form-grid {
grid-template-columns: 1fr;
}
}
.input-group {
margin-bottom: 15px;
}
.input-group label {
display: block;
margin-bottom: 8px;
font-weight: 600;
font-size: 14px;
color: #495057;
}
.input-group input, .input-group select {
width: 100%;
padding: 12px;
border: 1px solid #ced4da;
border-radius: 6px;
font-size: 16px;
transition: border-color 0.2s;
box-sizing: border-box;
}
.input-group input:focus {
border-color: #007bff;
outline: none;
}
.calc-btn {
grid-column: 1 / -1;
background-color: #007bff;
color: white;
border: none;
padding: 15px;
font-size: 18px;
font-weight: bold;
border-radius: 6px;
cursor: pointer;
width: 100%;
margin-top: 10px;
transition: background-color 0.2s;
}
.calc-btn:hover {
background-color: #0056b3;
}
.results-box {
grid-column: 1 / -1;
background-color: #ffffff;
border: 2px solid #28a745;
border-radius: 8px;
padding: 20px;
margin-top: 20px;
display: none;
}
.results-box h3 {
margin-top: 0;
color: #28a745;
text-align: center;
}
.result-row {
display: flex;
justify-content: space-between;
padding: 10px 0;
border-bottom: 1px solid #eee;
}
.result-row:last-child {
border-bottom: none;
}
.result-value {
font-weight: bold;
font-size: 18px;
}
.highlight-result {
font-size: 24px;
color: #28a745;
}
.article-content {
margin-top: 40px;
padding: 20px;
background: #fff;
}
.article-content h2 {
color: #2c3e50;
border-bottom: 2px solid #007bff;
padding-bottom: 10px;
margin-top: 30px;
}
.article-content h3 {
color: #495057;
margin-top: 25px;
}
.article-content p, .article-content li {
font-size: 16px;
color: #555;
margin-bottom: 15px;
}
.article-content ul {
padding-left: 20px;
}
.error-msg {
color: #dc3545;
text-align: center;
grid-column: 1 / -1;
display: none;
margin-top: 10px;
}
function calculateAffordability() {
// Get Input Values
var annualIncome = parseFloat(document.getElementById('annualIncome').value);
var monthlyDebt = parseFloat(document.getElementById('monthlyDebt').value);
var downPayment = parseFloat(document.getElementById('downPayment').value);
var interestRate = parseFloat(document.getElementById('interestRate').value);
var loanTermYears = parseFloat(document.getElementById('loanTerm').value);
var taxRatePercent = parseFloat(document.getElementById('propertyTaxRate').value);
// Error Handling
var errorMsg = document.getElementById('errorMsg');
var resultBox = document.getElementById('resultDisplay');
if (isNaN(annualIncome) || isNaN(interestRate) || annualIncome <= 0) {
errorMsg.style.display = 'block';
resultBox.style.display = 'none';
return;
}
errorMsg.style.display = 'none';
if (isNaN(monthlyDebt)) monthlyDebt = 0;
if (isNaN(downPayment)) downPayment = 0;
// 1. Calculate Gross Monthly Income
var grossMonthlyIncome = annualIncome / 12;
// 2. Calculate Max Housing Payment based on Ratios
// Front End (28% of Income)
var limitFront = grossMonthlyIncome * 0.28;
// Back End (36% of Income minus Debts)
var limitBack = (grossMonthlyIncome * 0.36) – monthlyDebt;
// The qualifying payment is the lesser of the two
var maxMonthlyTotal = Math.min(limitFront, limitBack);
// If debts are too high, max payment might be negative
if (maxMonthlyTotal Loan = HomePrice – DownPayment
// MortgagePayment = (Price – Down) * MFactor
// Total = (Price – Down) * MFactor + (Price * EscrowFactor)
// Total = Price*MFactor – Down*MFactor + Price*EscrowFactor
// Total + Down*MFactor = Price * (MFactor + EscrowFactor)
// Price = (Total + Down*MFactor) / (MFactor + EscrowFactor)
var r = (interestRate / 100) / 12;
var n = loanTermYears * 12;
// Mortgage Factor (Principal & Interest per dollar borrowed)
var mortgageFactor = 0;
if (interestRate === 0) {
mortgageFactor = 1 / n;
} else {
mortgageFactor = (r * Math.pow(1 + r, n)) / (Math.pow(1 + r, n) – 1);
}
// Calculate Max Home Price
var maxHomePrice = (maxMonthlyTotal + (downPayment * mortgageFactor)) / (mortgageFactor + monthlyEscrowFactor);
// Calculate derived values
var loanAmount = maxHomePrice – downPayment;
// Formatting helper
var formatter = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
maximumFractionDigits: 0
});
// Update DOM
document.getElementById('resHomePrice').innerHTML = formatter.format(maxHomePrice);
document.getElementById('resMonthlyPayment').innerHTML = formatter.format(maxMonthlyTotal);
document.getElementById('resLoanAmount').innerHTML = formatter.format(loanAmount);
// Show which ratio constrained the borrower
if (limitBack < limitFront) {
document.getElementById('resDTI').innerHTML = "36% (Back-End Ratio – Debts)";
} else {
document.getElementById('resDTI').innerHTML = "28% (Front-End Ratio – Income)";
}
resultBox.style.display = 'block';
}
Mortgage Affordability Calculator
30 Years
20 Years
15 Years
10 Years
Please enter valid positive numbers for Income and Interest Rate.
Affordability Estimate
Maximum Home Price:
–
Max Monthly Payment (P&I + Tax/Ins):
–
Loan Amount:
–
Debt-to-Income Ratio Used:
36%
How Much House Can I Afford?
Determining your budget is the first critical step in the home buying process. This Mortgage Affordability Calculator uses the standard 28/36 rule employed by lenders to estimate the maximum home price you can comfortably afford based on your income, debts, and down payment.
Understanding the 28/36 Rule
Lenders typically look at two key ratios when approving a mortgage:
- Front-End Ratio (28%): Your estimated 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 + student loans + car loans) should not exceed 36% of your gross monthly income.
Our calculator checks both scenarios and uses the lower limit to ensure a conservative, safe estimate of your buying power.
Key Factors Influencing Your Affordability
Several variables impact how much money a bank will lend you:
- Gross Annual Income: The higher your income, the more you can borrow. This includes salary, bonuses, and consistent freelance income.
- Monthly Debts: High existing debt lowers your buying power significantly because it eats into your Back-End Ratio.
- Down Payment: A larger down payment reduces the loan amount required, allowing you to buy a more expensive home for the same monthly payment.
- Interest Rate: Even a small increase in interest rates can drastically reduce your maximum affordable home price by increasing monthly interest costs.
What is Included in the Estimated Payment?
The "Max Monthly Payment" calculated above estimates your PITI: Principal, Interest, Taxes, and Insurance. We estimate property taxes based on the percentage provided (default 1.2%) and include a standard estimate for homeowners insurance to give you a realistic view of your monthly financial commitment.