Your credit score gets the headlines, but lenders make most decisions with a quieter number: your debt-to-income (DTI) ratio. It tells them how much of your income is already committed to payments — and whether you can afford one more. Here is how it works.
The DTI Formula
DTI = (Total Monthly Debt Payments ÷ Gross Monthly Income) × 100
- Gross income = your income before taxes
- Debt payments = the minimums and monthly obligations you must pay
Worked Example
Gross monthly income: $6,000. Monthly obligations:
- Car loan: $350
- Student loan: $250
- Credit card minimums: $200
- Total: $800
DTI = (800 ÷ 6,000) × 100 = 13.3% — excellent. Add a $1,400 mortgage and the total reaches $2,200, or 36.7%, which is right at the conventional-loan limit.
Front-End vs Back-End DTI
Lenders look at two ratios:
- Front-end (housing) ratio — housing payment only (mortgage, taxes, insurance, HOA), usually capped at 28%
- Back-end ratio — ALL monthly debts, usually capped at 36% (43% is the CFPB qualified-mortgage ceiling)
What Lenders Consider Good
| DTI | Verdict |
|---|---|
| Under 20% | ✅ Excellent — strong borrowing power |
| 20–35% | ✅ Good — most loans easily available |
| 36–43% | ⚠️ Borderline — conventional loans may need compensating factors |
| 43–50% | 🚩 High — FHA and some programs only |
| Over 50% | ❌ Very high — most lenders will decline |
DTI Matters for More Than Mortgages
Auto lenders, personal-loan issuers, and credit card companies all run DTI checks — usually targeting a back-end ratio under 40%. A high DTI is also the most common reason for credit limit decreases.
How to Lower Your DTI
1. Pay down balances — every dollar reduces your minimums (cards re-calculate minimums from your balance)
2. Avoid new debt — no new car or furniture loans in the months before applying
3. Increase income — overtime, side work, or a raise raise the denominator
4. Consolidate — a lower-rate consolidation loan can shrink total monthly payments
💡 Pro Tip: Don't pay off your cards and close them — that raises utilization and can backfire. Keep them open with a zero balance; your DTI drops and your score stays healthy.
What DTI Doesn't Tell You
DTI ignores your discretionary spending — two people with identical DTIs can have very different financial health. Lenders use DTI as a safety rule, not a full picture of your budget.
Try Our Tools
- Debt-to-Income Calculator — get your ratio in seconds
- Mortgage Calculator — test payments against your income
- Credit Card Payoff Calculator — shrink the debts dragging your ratio up
Related Reading
- Home Affordability: How Much House Can You Afford?
- Loan vs. Mortgage: What's the Difference?
- Debt Consolidation: When Combining Your Loans Actually Saves Money
- Credit Card Interest: How APR and Daily Compounding Work
The Consumer Financial Protection Bureau explains why the 43% DTI threshold matters for mortgages in its DTI explainer.
*Check your borrowing power in seconds with our free Debt-to-Income Calculator.*
