Please enter valid numbers for income, rate, and down payment.
You Can Afford a Home Costing:$0.00
Loan Amount:$0.00
Down Payment:$0.00
Est. Monthly Payment (PITI):$0.00
Debt-to-Income Used:0%
How Much House Can I Afford?
Determining your home buying budget is the most critical first step in the real estate journey. This Mortgage Affordability Calculator uses standard lender guidelines to estimate your purchasing power based on your income, debts, and down payment.
Understanding the 28/36 Rule
Most lenders use the 28/36 rule to determine how much money they will lend you:
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 (including housing costs plus car loans, student loans, and credit cards) should not exceed 36% of your gross monthly income.
Key Factors Affecting Your Affordability
Several variables impact the final price of the home you can purchase:
Interest Rate: A lower interest rate significantly increases your buying power because a larger portion of your monthly payment goes toward the principal rather than interest.
Down Payment: The more cash you put down upfront, the less you need to borrow, allowing you to buy a more expensive home with the same monthly payment.
Debt Load: Reducing your monthly recurring debts (like paying off a car note) frees up room in your "Back-End Ratio," directly increasing your mortgage eligibility.
Loan Term: A 30-year term offers lower monthly payments than a 15-year term, typically allowing you to qualify for a higher loan amount, though you will pay more interest over time.
What are Closing Costs?
Remember that your down payment isn't the only cash you need. Closing costs typically range from 2% to 5% of the loan amount. These include appraisal fees, title insurance, and origination fees. Ensure you have enough savings to cover both the down payment and these closing expenses.
function calculateAffordability() {
// 1. Get Inputs
var incomeAnnual = parseFloat(document.getElementById('annualIncome').value);
var monthlyDebts = parseFloat(document.getElementById('monthlyDebts').value) || 0;
var downPayment = parseFloat(document.getElementById('downPayment').value) || 0;
var interestRate = parseFloat(document.getElementById('interestRate').value);
var loanTermYears = parseInt(document.getElementById('loanTerm').value);
var annualTax = parseFloat(document.getElementById('propertyTax').value) || 0;
var annualInsurance = parseFloat(document.getElementById('insurance').value) || 0;
// 2. Validation
var errorDiv = document.getElementById('errorMsg');
var resultsDiv = document.getElementById('resultsArea');
if (isNaN(incomeAnnual) || isNaN(interestRate) || incomeAnnual <= 0) {
errorDiv.style.display = "block";
resultsDiv.style.display = "none";
return;
} else {
errorDiv.style.display = "none";
}
// 3. Logic: Determine Max Allowable Monthly Payment (PITI)
// Monthly Income
var incomeMonthly = incomeAnnual / 12;
// Front-End Limit (28% of Income)
var maxPaymentFront = incomeMonthly * 0.28;
// Back-End Limit (36% of Income minus debts)
var maxPaymentBack = (incomeMonthly * 0.36) – monthlyDebts;
// The bank takes the lower of the two
var maxAllowablePITI = Math.min(maxPaymentFront, maxPaymentBack);
// If debts are too high, affordability might be zero
if (maxAllowablePITI < 0) maxAllowablePITI = 0;
// Subtract Tax and Insurance to get Max Mortgage Payment (Principal + Interest)
var monthlyTax = annualTax / 12;
var monthlyIns = annualInsurance / 12;
var maxMortgagePayment = maxAllowablePITI – monthlyTax – monthlyIns;
if (maxMortgagePayment 0 ? maxAllowablePITI : 0) + monthlyDebts;
var actualDTI = (totalMonthlyObligation / incomeMonthly) * 100;
// 4. Update Output
resultsDiv.style.display = "block";
// Formatting function
var formatter = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
minimumFractionDigits: 0,
maximumFractionDigits: 0,
});
document.getElementById('maxHomePrice').innerHTML = formatter.format(maxHomePrice);
document.getElementById('loanAmountResult').innerHTML = formatter.format(maxLoanAmount);
document.getElementById('downPaymentResult').innerHTML = formatter.format(downPayment);
document.getElementById('monthlyPaymentResult').innerHTML = formatter.format(maxLoanAmount > 0 ? maxAllowablePITI : 0);
document.getElementById('dtiResult').innerHTML = actualDTI.toFixed(1) + "%";
}