Calculate your Front-End and Back-End DTI ratios to assess mortgage eligibility.
Please enter a valid income amount greater than zero.
Gross Monthly Income:$0.00
Total Monthly Debt:$0.00
Front-End Ratio (Housing):0%
Back-End Ratio (Total Debt):0%
Lender Assessment:…
Understanding Your Debt-to-Income (DTI) Ratio
Your Debt-to-Income (DTI) ratio is one of the most critical metrics lenders use to determine your ability to repay a loan. Whether you are applying for a mortgage, an auto loan, or a personal line of credit, understanding your DTI is the first step toward financial health.
What is DTI?
The DTI ratio compares your total monthly debt payments to your gross monthly income (income before taxes and deductions). It is expressed as a percentage. A lower percentage indicates that you have a good balance between debt and income, while a higher percentage suggests that you may be overleveraged.
Front-End vs. Back-End Ratio
Lenders typically look at two types of DTI ratios:
Front-End Ratio: This strictly measures your housing-related expenses (mortgage principal, interest, taxes, insurance, and HOA fees) against your gross income. Lenders generally prefer this to be under 28%.
Back-End Ratio: This includes your housing costs plus all other recurring monthly debts, such as credit cards, car loans, student loans, and alimony. Most lenders prefer a back-end ratio under 36%, though some conventional loans allow up to 43-50%.
Why Your DTI Score Matters
If your DTI is too high, lenders view you as a high-risk borrower. This can result in:
Denial of your loan application.
Higher interest rates, costing you thousands over the life of the loan.
Requirements for a larger down payment or a co-signer.
How to Improve Your DTI
If your calculation shows a percentage higher than 43%, consider paying down high-interest credit card debt or refinancing loans to lower monthly payments before applying for a mortgage. Increasing your income through a side hustle or salary negotiation will also naturally lower your DTI ratio.
function calculateDTI() {
// Get Inputs
var annualIncome = parseFloat(document.getElementById('annualIncome').value);
var monthlyHousing = parseFloat(document.getElementById('monthlyHousing').value);
var creditCards = parseFloat(document.getElementById('creditCards').value);
var carLoans = parseFloat(document.getElementById('carLoans').value);
var studentLoans = parseFloat(document.getElementById('studentLoans').value);
var otherDebt = parseFloat(document.getElementById('otherDebt').value);
// Validation: Ensure income is valid and > 0
var errorMsg = document.getElementById('errorMsg');
var resultsBox = document.getElementById('results');
if (isNaN(annualIncome) || annualIncome <= 0) {
errorMsg.style.display = 'block';
resultsBox.style.display = 'none';
return;
} else {
errorMsg.style.display = 'none';
}
// Sanitize optional inputs to 0 if empty/NaN
if (isNaN(monthlyHousing)) monthlyHousing = 0;
if (isNaN(creditCards)) creditCards = 0;
if (isNaN(carLoans)) carLoans = 0;
if (isNaN(studentLoans)) studentLoans = 0;
if (isNaN(otherDebt)) otherDebt = 0;
// Calculations
var grossMonthlyIncome = annualIncome / 12;
var totalNonHousingDebt = creditCards + carLoans + studentLoans + otherDebt;
var totalMonthlyDebt = monthlyHousing + totalNonHousingDebt;
var frontEndRatio = (monthlyHousing / grossMonthlyIncome) * 100;
var backEndRatio = (totalMonthlyDebt / grossMonthlyIncome) * 100;
// Format and Display Results
document.getElementById('resMonthlyIncome').innerText = '$' + grossMonthlyIncome.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('resTotalDebt').innerText = '$' + totalMonthlyDebt.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById('resFrontEnd').innerText = frontEndRatio.toFixed(2) + '%';
document.getElementById('resBackEnd').innerText = backEndRatio.toFixed(2) + '%';
// Assessment Logic
var assessment = "";
if (backEndRatio 36 && backEndRatio 43 && backEndRatio <= 50) {
assessment = "Caution. Your DTI is high. You may face higher interest rates or have difficulty qualifying for standard loans.";
document.getElementById('resAssessment').style.color = "#c0392b";
} else {
assessment = "High Risk. Most lenders will require you to lower your debt or increase income before approving a loan.";
document.getElementById('resAssessment').style.color = "#c0392b";
}
document.getElementById('resAssessment').innerText = assessment;
// Show Results
resultsBox.style.display = 'block';
}