Home Affordability Calculator
/* Scoped styles for the calculator to prevent theme conflicts */
.hac-calculator-container {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
max-width: 800px;
margin: 0 auto;
border: 1px solid #e2e8f0;
border-radius: 8px;
background-color: #ffffff;
box-shadow: 0 4px 6px rgba(0,0,0,0.05);
overflow: hidden;
}
.hac-header {
background-color: #2c3e50;
color: #ffffff;
padding: 20px;
text-align: center;
}
.hac-header h2 {
margin: 0;
font-size: 24px;
color: #ffffff;
}
.hac-grid {
display: flex;
flex-wrap: wrap;
padding: 20px;
gap: 20px;
}
.hac-inputs {
flex: 1;
min-width: 300px;
}
.hac-results {
flex: 1;
min-width: 300px;
background-color: #f8fafc;
border-radius: 8px;
padding: 20px;
display: flex;
flex-direction: column;
justify-content: center;
}
.hac-form-group {
margin-bottom: 15px;
}
.hac-label {
display: block;
font-weight: 600;
margin-bottom: 5px;
color: #4a5568;
font-size: 14px;
}
.hac-input {
width: 100%;
padding: 10px;
border: 1px solid #cbd5e0;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box; /* Critical for padding */
}
.hac-input:focus {
outline: none;
border-color: #3182ce;
box-shadow: 0 0 0 3px rgba(66, 153, 225, 0.2);
}
.hac-btn {
width: 100%;
background-color: #3182ce;
color: white;
border: none;
padding: 12px;
font-size: 16px;
font-weight: bold;
border-radius: 4px;
cursor: pointer;
transition: background-color 0.2s;
margin-top: 10px;
}
.hac-btn:hover {
background-color: #2b6cb0;
}
.hac-result-row {
margin-bottom: 20px;
text-align: center;
border-bottom: 1px solid #e2e8f0;
padding-bottom: 15px;
}
.hac-result-row:last-child {
border-bottom: none;
margin-bottom: 0;
}
.hac-result-label {
font-size: 14px;
color: #718096;
margin-bottom: 5px;
text-transform: uppercase;
letter-spacing: 0.5px;
}
.hac-result-value {
font-size: 28px;
font-weight: 800;
color: #2d3748;
}
.hac-result-sub {
font-size: 13px;
color: #718096;
margin-top: 5px;
}
.hac-error {
color: #e53e3e;
font-size: 14px;
margin-top: 10px;
display: none;
text-align: center;
}
/* Article Styles */
.hac-content {
max-width: 800px;
margin: 40px auto;
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
line-height: 1.6;
color: #2d3748;
}
.hac-content h2 {
color: #2c3e50;
border-bottom: 2px solid #3182ce;
padding-bottom: 10px;
margin-top: 30px;
}
.hac-content h3 {
color: #2c3e50;
margin-top: 25px;
}
.hac-content p {
margin-bottom: 15px;
}
.hac-content ul {
margin-bottom: 15px;
padding-left: 20px;
}
.hac-content li {
margin-bottom: 8px;
}
@media (max-width: 600px) {
.hac-grid {
flex-direction: column;
}
}
Maximum Home Price
$0
Based on income & debts
Max Monthly Payment
$0
Including Tax & Insurance
How Much House Can You Really Afford?
Determining your budget is the first critical step in the home buying process. This Home Affordability Calculator uses the standard debt-to-income (DTI) ratios used by mortgage lenders to provide a realistic estimate of your purchasing power.
Understanding the 28/36 Rule
Most financial experts and lenders follow the 28/36 rule to determine affordability:
- Front-End Ratio (28%): Your monthly housing costs (mortgage principal, interest, property 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.
Our calculator analyzes both ratios and uses the lower (more conservative) figure to ensure you don't overextend yourself financially.
Key Factors Affecting Your Affordability
Several variables impact how much house you can buy:
- Interest Rates: A higher interest rate increases your monthly payment, significantly reducing the loan amount you can qualify for. Even a 1% difference can change your buying power by tens of thousands of dollars.
- Down Payment: The more cash you put down upfront, the more expensive the home you can afford, as it reduces the amount you need to borrow.
- Monthly Debts: High existing debts (like car payments or student loans) reduce your back-end ratio allowance, directly lowering your mortgage capacity.
- Property Taxes & Insurance: These recurring costs are part of your monthly payment (PITI). Homes in high-tax areas will lower your maximum loan amount compared to low-tax areas.
Tips to Increase Your Home Buying Power
If the result isn't quite what you hoped for, consider these strategies: pay down high-interest consumer debt to lower your monthly obligations, save for a larger down payment, or shop around for a lower interest rate. Improving your credit score can also help you secure better loan terms.
function calculateAffordability() {
// 1. Get input values
var annualIncome = parseFloat(document.getElementById("hacAnnualIncome").value);
var monthlyDebts = parseFloat(document.getElementById("hacMonthlyDebts").value);
var downPayment = parseFloat(document.getElementById("hacDownPayment").value);
var interestRate = parseFloat(document.getElementById("hacInterestRate").value);
var loanTermYears = parseFloat(document.getElementById("hacLoanTerm").value);
var annualTax = parseFloat(document.getElementById("hacPropertyTax").value);
var annualInsurance = parseFloat(document.getElementById("hacInsurance").value);
// 2. Validation
var errorDiv = document.getElementById("hacErrorMessage");
if (isNaN(annualIncome) || isNaN(interestRate) || isNaN(loanTermYears)) {
errorDiv.style.display = "block";
errorDiv.innerHTML = "Please fill in all required fields (Income, Rate, Term).";
return;
}
// Handle optional fields as 0 if empty
if (isNaN(monthlyDebts)) monthlyDebts = 0;
if (isNaN(downPayment)) downPayment = 0;
if (isNaN(annualTax)) annualTax = 0;
if (isNaN(annualInsurance)) annualInsurance = 0;
errorDiv.style.display = "none";
// 3. Calculation Logic
var monthlyIncome = annualIncome / 12;
var monthlyTax = annualTax / 12;
var monthlyInsurance = annualInsurance / 12;
// Lenders typically use 28% front-end and 36% back-end ratios
var frontEndLimit = monthlyIncome * 0.28;
var backEndLimit = (monthlyIncome * 0.36) – monthlyDebts;
// The maximum allowable PITI (Principal, Interest, Tax, Insurance) is the lesser of the two
var maxMonthlyPITI = Math.min(frontEndLimit, backEndLimit);
// If debts are too high, max payment might be negative
if (maxMonthlyPITI <= 0) {
document.getElementById("hacResultPrice").innerText = "$0";
document.getElementById("hacResultPayment").innerText = "$0";
document.getElementById("hacResultLoan").innerText = "$0";
errorDiv.style.display = "block";
errorDiv.innerHTML = "Your current monthly debts exceed the allowable debt-to-income ratio.";
return;
}
// Subtract Tax and Insurance to find Max Mortgage Payment (Principal + Interest)
var maxMortgagePayment = maxMonthlyPITI – monthlyTax – monthlyInsurance;
if (maxMortgagePayment < 0) {
document.getElementById("hacResultPrice").innerText = "$0";
document.getElementById("hacResultPayment").innerText = "$" + Math.floor(maxMonthlyPITI).toLocaleString();
document.getElementById("hacResultLoan").innerText = "$0";
errorDiv.style.display = "block";
errorDiv.innerHTML = "Taxes and Insurance exceed your maximum monthly housing budget.";
return;
}
// Calculate Max Loan Amount using PV formula
// PV = PMT * (1 – (1+r)^-n) / r
var r = (interestRate / 100) / 12; // Monthly interest rate
var n = loanTermYears * 12; // Total number of payments
var maxLoanAmount = 0;
if (r === 0) {
maxLoanAmount = maxMortgagePayment * n;
} else {
maxLoanAmount = maxMortgagePayment * (1 – Math.pow(1 + r, -n)) / r;
}
// Max Home Price = Loan Amount + Down Payment
var maxHomePrice = maxLoanAmount + downPayment;
// 4. Update UI
var formatter = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
maximumFractionDigits: 0
});
document.getElementById("hacResultPrice").innerText = formatter.format(maxHomePrice);
document.getElementById("hacResultPayment").innerText = formatter.format(maxMonthlyPITI);
document.getElementById("hacResultLoan").innerText = formatter.format(maxLoanAmount) + " Loan";
}