Before a bank approves your mortgage, car loan, or personal loan, it calculates one number above almost everything else: your debt-to-income ratio. Understanding DTI — what it is, how it's calculated, and what lenders want to see — can mean the difference between approval and rejection.
What Is Debt-to-Income Ratio?
DTI is simply your total monthly debt payments divided by your gross monthly income, expressed as a percentage. If you earn $6,000/month and pay $1,800 in debt obligations, your DTI is 30%. The formula: DTI = Monthly Debt Payments ÷ Gross Monthly Income × 100.
What Counts as "Debt"?
Lenders include all recurring monthly obligations:
- Mortgage or rent payment (proposed or current)
- Car loans and lease payments
- Student loan payments
- Minimum credit card payments
- Personal loan payments
- Child support or alimony
They do not count utilities, groceries, subscriptions, insurance premiums, or irregular expenses.
What's a Good DTI?
Lenders generally use these thresholds:
- Under 20% — Excellent. You'll qualify for the best rates.
- 20–36% — Good. Well within most lenders' comfort zone.
- 37–43% — Acceptable but tight. Most conventional mortgages allow up to 43%.
- 44–49% — Risky. Some FHA loans allow this but expect higher rates.
- 50%+ — Most lenders will decline. Half your income going to debt is a significant red flag.
💡 The 28/36 rule: Many financial advisors recommend keeping your housing costs under 28% of gross income and total debt under 36%. This is more conservative than most lenders require but protects your financial flexibility.
Front-End vs Back-End DTI
Mortgage lenders often calculate two DTI numbers. Front-end DTI includes only housing costs (mortgage principal, interest, taxes, insurance). Back-end DTI includes all monthly debt obligations. When lenders say "DTI," they usually mean back-end. FHA loans allow front-end DTI up to 31% and back-end up to 43%.
How to Lower Your DTI
Two levers: earn more or owe less. In practice: pay down high-balance debts (especially cards with large minimums), avoid taking on new debt before a mortgage application, and consider ways to document additional income streams. Even dropping your DTI from 44% to 41% by paying off a car loan can unlock loan approval.