.hac-wrapper {
max-width: 800px;
margin: 0 auto;
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
color: #333;
line-height: 1.6;
}
.hac-calculator-box {
background: #f8f9fa;
border: 1px solid #e9ecef;
border-radius: 8px;
padding: 25px;
margin-bottom: 40px;
box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}
.hac-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 30px;
}
@media (max-width: 768px) {
.hac-grid {
grid-template-columns: 1fr;
}
}
.hac-input-group {
margin-bottom: 15px;
}
.hac-input-group label {
display: block;
font-weight: 600;
margin-bottom: 5px;
font-size: 0.95em;
color: #495057;
}
.hac-input-group input, .hac-input-group select {
width: 100%;
padding: 10px;
border: 1px solid #ced4da;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
}
.hac-input-group input:focus {
border-color: #4dabf7;
outline: none;
box-shadow: 0 0 0 3px rgba(77, 171, 247, 0.25);
}
.hac-btn {
background-color: #228be6;
color: white;
border: none;
padding: 12px 20px;
font-size: 16px;
font-weight: 700;
border-radius: 4px;
cursor: pointer;
width: 100%;
transition: background-color 0.2s;
margin-top: 10px;
}
.hac-btn:hover {
background-color: #1c7ed6;
}
.hac-results {
background: #fff;
border: 1px solid #dee2e6;
border-radius: 6px;
padding: 20px;
text-align: center;
}
.hac-main-result {
font-size: 2em;
font-weight: 800;
color: #228be6;
margin: 10px 0;
}
.hac-sub-result {
font-size: 1.1em;
color: #495057;
margin-bottom: 20px;
border-bottom: 1px solid #eee;
padding-bottom: 10px;
}
.hac-breakdown {
text-align: left;
font-size: 0.9em;
}
.hac-breakdown-row {
display: flex;
justify-content: space-between;
margin-bottom: 8px;
padding-bottom: 8px;
border-bottom: 1px dashed #eee;
}
.hac-breakdown-row:last-child {
border-bottom: none;
}
.hac-content h2 {
color: #343a40;
margin-top: 30px;
}
.hac-content p {
margin-bottom: 15px;
}
.hac-content ul {
margin-bottom: 20px;
padding-left: 20px;
}
.hac-content li {
margin-bottom: 8px;
}
.hac-error {
color: #fa5252;
font-weight: bold;
margin-top: 10px;
display: none;
}
Home Affordability Calculator
You Can Afford A House Up To
$0
Estimated Monthly Payment: $0
Monthly Breakdown Estimate
Principal & Interest:
$0
Property Taxes:
$0
Homeowners Insurance:
$0
HOA Fees:
$0
How Much House Can I Afford?
Determine your buying power with our specialized Home Affordability Calculator. Unlike a standard mortgage calculator which starts with the home price, this tool works backwards from your income and debts to find the maximum property value aligned with financial prudence.
Understanding the Calculation Logic
This calculator uses the standard debt-to-income (DTI) ratios utilized by most mortgage lenders to qualify borrowers. We calculate your budget based on two primary constraints:
- Front-End Ratio (28%): Lenders generally prefer that your housing costs (Principal, Interest, Taxes, Insurance, and HOA) do not exceed 28% of your gross monthly income.
- Back-End Ratio (36%): Your total monthly debt obligations, including your new mortgage and existing debts (car loans, student loans, credit cards), should typically not exceed 36% of your gross monthly income.
The calculator selects the lower (more conservative) figure from these two ratios to ensure you remain within a safe borrowing limit.
Key Factors Affecting Your Affordability
Several variables drastically impact the price of the home you can purchase:
- Down Payment: A larger down payment reduces the loan amount required, directly increasing your maximum purchase price.
- Interest Rates: Even a 1% difference in rates can change your buying power by tens of thousands of dollars.
- Existing Debt: Reducing monthly obligations like credit card minimums or car payments frees up room in your DTI ratio for a larger mortgage.
- Property Taxes & HOA: High taxes or Homeowners Association fees eat into your monthly payment capacity, lowering the mortgage amount you can support.
What is Included in the PITI Payment?
Your estimated monthly payment is often referred to as PITI:
- Principal: The portion going towards paying off the loan balance.
- Interest: The cost of borrowing the money.
- Taxes: Property taxes assessed by your local government (estimated here at 1.2% annually).
- Insurance: Hazard insurance to protect the property (estimated here at 0.5% annually).
function calculateAffordability() {
// 1. Get Input Values
var annualIncome = parseFloat(document.getElementById("hacAnnualIncome").value) || 0;
var monthlyDebts = parseFloat(document.getElementById("hacMonthlyDebts").value) || 0;
var downPayment = parseFloat(document.getElementById("hacDownPayment").value) || 0;
var interestRate = parseFloat(document.getElementById("hacInterestRate").value) || 0;
var loanTermYears = parseFloat(document.getElementById("hacLoanTerm").value) || 30;
var taxRateAnnual = parseFloat(document.getElementById("hacPropTax").value) || 0;
var hoaMonthly = parseFloat(document.getElementById("hacHOA").value) || 0;
var errorDiv = document.getElementById("hacError");
// Validation
if (annualIncome <= 0) {
errorDiv.style.display = "block";
errorDiv.innerText = "Please enter a valid annual income.";
return;
} else {
errorDiv.style.display = "none";
}
// 2. Constants & Conversions
var monthlyIncome = annualIncome / 12;
var insuranceRateAnnual = 0.5; // Estimated 0.5% annual insurance rate
// 3. Determine Max Allowable Monthly Housing Payment
// Rule 1: Front-End Ratio (28% of income for housing)
var limitFrontEnd = monthlyIncome * 0.28;
// Rule 2: Back-End Ratio (36% of income for housing + debts)
// Max Total Debt = 36% of Income.
// Available for Housing = (36% of Income) – Existing Debts.
var limitBackEnd = (monthlyIncome * 0.36) – monthlyDebts;
// The strict limit is the lower of the two
var maxMonthlyPayment = Math.min(limitFrontEnd, limitBackEnd);
// If debts are too high, result might be negative
if (maxMonthlyPayment <= 0) {
document.getElementById("hacMaxPrice").innerText = "$0";
document.getElementById("hacMonthlyPayment").innerText = "Debt too high";
document.getElementById("hacBreakdownPI").innerText = "$0";
document.getElementById("hacBreakdownTax").innerText = "$0";
document.getElementById("hacBreakdownIns").innerText = "$0";
document.getElementById("hacBreakdownHOA").innerText = "$0";
return;
}
// 4. Reverse Calculate Loan Amount
// Formula: MaxPayment = (Loan * M) + (HomePrice * Tax/12) + (HomePrice * Ins/12) + HOA
// Note: HomePrice = Loan + DownPayment
// So: MaxPayment = (Loan * M) + ((Loan+Down) * T_m) + ((Loan+Down) * I_m) + HOA
var monthlyInterestRate = (interestRate / 100) / 12;
var numberOfPayments = loanTermYears * 12;
var taxRateMonthly = (taxRateAnnual / 100) / 12;
var insRateMonthly = (insuranceRateAnnual / 100) / 12;
// Mortgage Factor (M)
var mortgageFactor = 0;
if (monthlyInterestRate === 0) {
mortgageFactor = 1 / numberOfPayments;
} else {
mortgageFactor = (monthlyInterestRate * Math.pow(1 + monthlyInterestRate, numberOfPayments)) / (Math.pow(1 + monthlyInterestRate, numberOfPayments) – 1);
}
// Rearranging the equation to solve for Loan:
// MaxPayment – HOA = Loan(M) + Loan(T_m) + Loan(I_m) + Down(T_m) + Down(I_m)
// MaxPayment – HOA – Down(T_m + I_m) = Loan * (M + T_m + I_m)
// Loan = (MaxPayment – HOA – Down(T_m + I_m)) / (M + T_m + I_m)
var numerator = maxMonthlyPayment – hoaMonthly – (downPayment * (taxRateMonthly + insRateMonthly));
var denominator = mortgageFactor + taxRateMonthly + insRateMonthly;
var maxLoanAmount = numerator / denominator;
// Handle case where maxLoanAmount is negative (meaning expenses/taxes on downpayment alone exceed budget)
if (maxLoanAmount < 0) maxLoanAmount = 0;
var maxHomePrice = maxLoanAmount + downPayment;
// 5. Calculate Breakdown based on computed MaxHomePrice
var taxMonthly = maxHomePrice * taxRateMonthly;
var insMonthly = maxHomePrice * insRateMonthly;
var piMonthly = maxLoanAmount * mortgageFactor;
// Total PITI + HOA (Should match maxMonthlyPayment close enough)
var totalMonthly = piMonthly + taxMonthly + insMonthly + hoaMonthly;
// 6. Display Results
// Formatting helper
var fmtMoney = function(num) {
return "$" + num.toLocaleString("en-US", {minimumFractionDigits: 0, maximumFractionDigits: 0});
};
document.getElementById("hacMaxPrice").innerText = fmtMoney(maxHomePrice);
document.getElementById("hacMonthlyPayment").innerText = fmtMoney(totalMonthly) + " /mo";
document.getElementById("hacBreakdownPI").innerText = fmtMoney(piMonthly);
document.getElementById("hacBreakdownTax").innerText = fmtMoney(taxMonthly);
document.getElementById("hacBreakdownIns").innerText = fmtMoney(insMonthly);
document.getElementById("hacBreakdownHOA").innerText = fmtMoney(hoaMonthly);
}