Debt-to-Income (DTI) Calculator
Calculate your front-end and back-end debt-to-income ratios instantly to see if you qualify for conventional, FHA, and VA mortgage lending programs.
$
Total pre-tax income before taxes and payroll deductions
$
Mortgage Principal, Interest, Taxes, Insurance & HOA (or rent)
$
Monthly minimum car payments across all vehicles
$
Monthly minimum payment reporting on credit
$
Sum of monthly minimums (not total credit balances)
$
Personal loans, child support, alimony, or medical installment debt
Back-End DTI (Total Debt)
34.7%
Conventional Ready
Front-End DTI (Housing Only)
24.0%
Within 28% Rule
Excellent (≤36%)
Acceptable (36–45%)
FHA Window (45–50%)
High Risk (>50%)
0%
28% (Front-End)
36% (Conventional)
43% (Standard FHA)
50%+
Total Monthly Debt Service
$2,600 / mo
Housing payment + non-housing obligations
Non-Housing Monthly Debt
$800 / mo
Auto, student loans, and credit cards
Max Total Debt (36% Conventional)
$2,700 / mo
Optimal debt cap for prime interest rates
Debt Payoff Needed (for 36% DTI)
$0 / mo
Your back-end DTI is already below 36%
How to Use This Calculator
- Select Your Currency: Choose from 8 supported currencies ($ USD, € EUR, £ GBP, CAD, AUD, INR, JPY, or CHF). All calculations adapt immediately.
- Input Gross Monthly Income: Enter your total monthly income before federal, state, and payroll deductions. Include reliable bonuses, overtime, or verified co-borrower income.
- Enter Proposed Housing Payments: Include your estimated full housing payment (Principal, Interest, Real Estate Taxes, Homeowners Insurance, and HOA fees).
- List Minimum Monthly Debt Obligations: Enter minimum contractual payments for cars, student loans, and credit cards. Do not enter everyday expenses like groceries, internet, or utilities.
- Review Loan Qualification Readiness: Evaluate both front-end (housing) and back-end (total debt) percentages against standard Fannie Mae, Freddie Mac, and FHA qualification limits.
The Formula
Underwriting guidelines rely on two standard mathematical ratios to evaluate a borrower's capacity to handle monthly mortgage payments alongside existing debt obligations.
Front-End DTI (Housing Ratio):
Front-End DTI % = (Proposed Monthly Housing Expense / Gross Monthly Income) × 100
Back-End DTI (Total Debt Ratio):
Back-End DTI % = [(Proposed Housing Expense + Total Other Recurring Debts) / Gross Monthly Income] × 100
Maximum Allowable Debt at 36% Benchmark:
Max Debt (36%) = Gross Monthly Income × 0.36
Required Monthly Debt Reduction:
Reduction Needed = Total Monthly Debt - Max Debt (36%)
(If Total Monthly Debt ≤ Max Debt, Reduction = $0)
Parameter Explanations:
- Gross Monthly Income: The baseline denominator for all mortgage affordability models. Lenders look for steady, two-year verified earning history.
- Housing Expense (PITI): The complete monthly carrying cost of the property, including principal repayment, interest charges, annual property tax prorations, private mortgage insurance (if down payment < 20%), and condo/HOA dues.
- Non-Housing Recurring Debts: Contractual minimum monthly obligations appearing on credit bureau reports. If a credit card has a $5,000 balance but a $150 minimum payment, only $150 enters the DTI formula.
Example Calculation
Consider a homebuyer earning $7,500 per month gross income preparing to purchase a single-family home with the following monthly expenses:
Financial Breakdown:
• Gross Monthly Income: $7,500
• Proposed Housing (PITI + HOA): $1,800
• Car Payment: $400
• Student Loan Payment: $250
• Credit Card Minimums: $150
• Total Non-Housing Debt: $400 + $250 + $150 = $800
• Total Monthly Debt Obligations: $1,800 + $800 = $2,600
• Gross Monthly Income: $7,500
• Proposed Housing (PITI + HOA): $1,800
• Car Payment: $400
• Student Loan Payment: $250
• Credit Card Minimums: $150
• Total Non-Housing Debt: $400 + $250 + $150 = $800
• Total Monthly Debt Obligations: $1,800 + $800 = $2,600
Step 1: Calculate Front-End DTI (Housing Ratio)
Front-End DTI = ($1,800 / $7,500) × 100 = 24.0%
Result: Safely below the conventional 28% front-end threshold.
Front-End DTI = ($1,800 / $7,500) × 100 = 24.0%
Result: Safely below the conventional 28% front-end threshold.
Step 2: Calculate Back-End DTI (Total Debt Ratio)
Back-End DTI = ($2,600 / $7,500) × 100 = 34.7%
Result: Well below the prime conventional 36% limit.
Back-End DTI = ($2,600 / $7,500) × 100 = 34.7%
Result: Well below the prime conventional 36% limit.
Underwriting Verdict: The applicant achieves Conventional Ready status. With a 34.7% back-end DTI and 24% front-end DTI, this profile qualifies for standard prime conventional financing with zero required debt reductions.
Frequently Asked Questions
What is a good debt-to-income (DTI) ratio to buy a house?
Mortgage lenders generally prefer a back-end DTI of 36% or less, with housing costs (front-end) not exceeding 28%. However, conventional loans approved through Fannie Mae Desktop Underwriter (DU) often allow up to 45% or 50% with strong credit, while FHA loans frequently permit up to 50% with compensating factors.
What is the difference between front-end and back-end DTI?
Front-end DTI measures only your proposed monthly housing payment (mortgage principal, interest, taxes, insurance, and HOA fees) divided by gross monthly income. Back-end DTI includes housing plus all recurring debt payments like auto loans, student loans, and credit cards.
What is the maximum DTI allowed for conventional and FHA mortgages?
The standard baseline for manually underwritten conventional loans is 36%, stretching to 45%–50% via automated underwriting systems. FHA loans standardly benchmark 31% front-end and 43% back-end, but automated underwriting regularly approves back-end ratios up to 50% for qualified applicants.
What debts are included in DTI calculations?
DTI calculations include contractual recurring debts appearing on credit reports: auto loans, student loans, personal loans, minimum credit card payments, child support, and alimony. Routine living expenses like groceries, cell phone bills, and streaming services are not included.
How can I quickly lower my DTI before applying for a loan?
You can quickly lower your DTI by paying off small credit card balances, refinancing high-payment auto loans, having a cosigner, or increasing verified gross income. Eliminating a $400 car payment on a $6,000 monthly income drops your back-end DTI by nearly 7 percentage points.