What DTI means to lenders
Debt-to-income (DTI) ratio is the percentage of your monthly gross income that goes toward debt payments. Mortgage lenders care about two flavors: front-end DTI (housing costs only, ideally ≤28%) and back-end DTI (all debt, ideally ≤36%). Conventional loans typically cap back-end DTI at 43%; FHA loans allow up to 50% in some cases.
The 28/36 rule
This classic rule of thumb says: spend no more than 28% of gross monthly income on housing, and no more than 36% on all debt combined. It's not a hard requirement, but lenders use it as a sanity check and so should you.
How to lower your DTI
- Pay down existing debt — especially credit cards, since they often carry the highest minimums relative to balance.
- Increase income (side gig, raise, new job) — the denominator grows while the numerator stays put.
- Avoid taking on new debt in the 6–12 months before applying for a mortgage.
- Refinance existing loans to lower monthly payments (though this often extends the term and increases total interest).
Student loans in income-driven repayment (IDR) plans count toward DTI using the actual payment amount — even if it's $0. Get a payment letter from your servicer before applying for a mortgage.
Frequently asked questions
What is a good debt-to-income ratio?
For conventional mortgages, lenders prefer 36% or less back-end DTI (43% is the hard cap for most qualified mortgages). FHA loans allow up to 50%. For personal loans, most lenders want under 40%. Lower is always better — under 20% is excellent.
Does DTI affect my credit score?
Not directly. Credit scoring models don't use income, so DTI isn't part of your FICO score. However, high DTI leads to higher credit utilization (which IS in your score) and makes new credit harder to get.
What's included in monthly debt payments?
All recurring debt obligations: mortgage/rent, auto loans, student loans, minimum credit card payments, personal loans, child support, alimony, and any other regular debt payments. Utility bills, groceries, and discretionary spending are NOT included.
How can I lower my DTI quickly?
Three options: (1) pay down existing debt, especially credit cards, (2) increase income through a raise, side gig, or new job, (3) refinance existing loans to lower monthly payments (though this often extends the term). The fastest is paying down credit cards.
Does my spouse's debt count toward my DTI?
If applying jointly, yes. If applying individually, lenders typically still consider spouse's debt if you live in a community property state (AZ, CA, ID, LA, NV, NM, TX, WA, WI). For mortgages, the spouse's debt almost always counts.
Why is my DTI different from what my lender calculated?
Lenders may include debts you forgot (deferred student loans, accounts in collections, child support). They also use the minimum payment shown on your credit report, which may differ from what you actually pay. Always pull your own credit report before applying.
Can I get a mortgage with DTI above 43%?
Possibly. Some lenders offer 'non-QM' (non-qualified mortgage) loans with DTI up to 50%, but rates are higher and underwriting is stricter. FHA loans allow up to 50% DTI with compensating factors like significant reserves or residual income.
Glossary of key terms
- Front-end DTI
- Housing costs (PITI + HOA) divided by gross monthly income. Also called the 'housing ratio.' Conventional loans prefer ≤28%.
- Back-end DTI
- All monthly debt payments divided by gross monthly income. Conventional loans cap at 43-36%.
- 28/36 Rule
- Classic rule of thumb: spend ≤28% of gross income on housing, ≤36% on all debt combined.
- Qualified Mortgage (QM)
- A mortgage category that meets Consumer Financial Protection Bureau rules, including a 43% DTI cap. Most conventional loans are QMs.
- PITI
- Principal, Interest, Taxes, Insurance — the four components of a monthly mortgage payment. Lenders use PITI in DTI calculations.
Common mistakes to avoid
- Forgetting to include deferred student loans — most lenders now impute a payment even if $0
- Not including child support or alimony payments
- Counting utility bills or subscriptions (these aren't debt payments)
- Using net income instead of gross income — DTI is always based on gross
- Ignoring debts that are in your spouse's name when applying jointly
Pro tips
- Pay down credit cards BEFORE applying for a mortgage — lower utilization improves both your credit score AND your DTI.
- Avoid taking on new debt (auto loans, furniture financing, etc.) in the 6-12 months before a mortgage application.
- If your DTI is borderline, ask the lender about 'manual underwriting' — humans can consider compensating factors that automated systems reject.
- Student loans in income-driven repayment count at the actual payment amount, even if it's $0 — get a payment letter from your servicer before applying.
- Consolidating high-payment debts into a lower-payment personal loan can temporarily improve DTI — but make sure you don't run up the old accounts again.
Results are estimates for educational purposes only and not financial advice. Consult a licensed professional for advice specific to your situation.