How to Calculate Your Debt-to-Income Ratio for a Mortgage
What Is Debt-to-Income Ratio?
Your debt-to-income ratio (DTI) is the percentage of your gross monthly income that goes toward debt payments. It is one of the most important numbers mortgage lenders evaluate — often more important than your credit score. A low DTI signals that you have enough income to comfortably handle a mortgage payment on top of existing debts.
Formula: DTI = Total monthly debt payments / Gross monthly income × 100
Example: $6,500 gross monthly income. Debts: $350 car payment + $250 student loans + $150 credit card minimums = $750/month. DTI = $750 / $6,500 = 11.5%. Adding a $1,800 mortgage payment: new DTI = $2,550 / $6,500 = 39.2%. Use our DTI calculator to compute yours.
Front-End vs Back-End DTI
| DTI type | What it includes | Lender maximum | Ideal target |
|---|---|---|---|
| Front-end (housing) | Mortgage P&I + property tax + insurance + HOA | 28-31% | Under 25% |
| Back-end (total) | All housing costs + all other debt payments | 36-50% (varies by loan) | Under 36% |
Most lenders focus on back-end DTI. Here are the maximum DTI limits by loan type:
| Loan type | Max DTI | Notes |
|---|---|---|
| Conventional | 45% (up to 50% with strong compensating factors) | Credit score 720+, large reserves help |
| FHA | 43% standard (up to 57% with compensating factors) | More flexible for lower-credit borrowers |
| VA | 41% guideline (no hard cap) | VA uses residual income test as primary measure |
| USDA | 41% (front-end 29%) | Stricter than FHA |
Which Debts Count in DTI Calculations
| Debt type | Counted? | How it is calculated |
|---|---|---|
| Mortgage / rent | Yes | Proposed mortgage payment (PITI + HOA) |
| Car loans | Yes | Monthly payment (unless <10 payments left) |
| Student loans | Yes | Actual payment or 0.5-1% of balance if deferred/IBR |
| Credit card minimums | Yes | Minimum payment shown on statement |
| Child support / alimony | Yes | Court-ordered payment amount |
| Personal loans | Yes | Monthly payment |
| Utilities, phone, insurance | No | Not reported as debt |
| Medical bills | Usually no | Unless in collections and reported |
| 401(k) loans | Yes | Monthly repayment amount |
How to Lower Your DTI Before Applying
1. Pay off small debts entirely. Eliminating a $150/month car payment or $200/month personal loan drops your DTI immediately. If a debt has fewer than 10 payments remaining, some lenders will exclude it.
2. Pay down credit card balances. Reducing your balance lowers the minimum payment used in DTI. Pay a $5,000 card down to $1,000 and the minimum drops from $150 to $35 — reducing DTI by $115/month.
3. Increase your income. A raise, side gig, or overtime can lower DTI. If you can document 2 years of side income on tax returns, lenders will count it. Use our salary calculator to model the impact.
4. Avoid new debt. Do not finance a car, open new credit cards, or take personal loans in the 6-12 months before applying for a mortgage. Every new payment increases your DTI.
5. Refinance student loans to lower payments. Extending the term from 10 to 25 years reduces the monthly payment (and DTI), though it increases total interest. Only do this if you need the lower DTI to qualify.
DTI vs What You Can Actually Afford
Just because a lender approves you at 43% DTI does not mean you should borrow that much. At 43% DTI on $6,500/month income, your total debts are $2,795/month — leaving $3,705 for everything else: groceries, utilities, insurance, transportation, savings, and discretionary spending. Many financial planners recommend keeping total DTI under 36% and housing under 25% for financial comfort. Use our mortgage qualification calculator and budget calculator to find your comfortable limit.
Updated for 2026 Economic Year.