Your credit score tells a lender whether you pay your bills. Your debt-to-income ratio (DTI) tells them whether you can afford to pay a new one. Most loan denials that surprise buyers come down to DTI — not credit.
The Simple Math
DTI is a fraction:
DTI = Total monthly debt payments ÷ Gross monthly income
If you earn $7,000 a month before taxes and pay $500 in car loans plus a $1,400 mortgage payment, your back-end DTI is:
$1,900 ÷ $7,000 = 27%
Front-End vs. Back-End DTI
Lenders calculate two versions:
Front-end DTI (housing ratio): Only your housing payment — principal, interest, taxes, insurance, and any HOA dues (PITI). Most conventional loans want this below 28%.
Back-end DTI (total debt ratio): Your housing payment plus all other monthly obligations — car loans, student loans, credit card minimums, personal loans, child support. This is the number underwriters focus on most.
What DTI Do You Need?
| Loan type | Max back-end DTI | Notes |
|---|---|---|
| Conventional | 45%–50% | 45% preferred; 50% requires compensating factors |
| FHA | 50%–57% | Higher end requires strong compensating factors |
| VA | No hard cap | Lender discretion; 41% is a common threshold |
| USDA | 41% | Stricter program guidelines |
These are ceilings, not targets. A DTI above 43% will survive underwriting — barely. Below 36% gives you the most options and the most negotiating power on rate.
What Counts as a Monthly Debt Payment?
Included in DTI:
- Car loans and leases
- Student loan minimums (even if deferred — lenders impute a payment)
- Credit card minimum payments
- Personal loans
- Child support or alimony
- Co-signed loans that appear on your credit report
Not included:
- Utilities, groceries, gas, subscriptions
- Insurance premiums (auto, health)
- Cell phone or streaming bills
How to Lower Your DTI Before Applying
Pay down revolving debt first. Paying off a credit card eliminates its minimum payment entirely. Paying down an installment loan (car, student) reduces the payment only slightly until full payoff — less impactful dollar-for-dollar on DTI.
Avoid new debt. A new car loan 60 days before closing can derail a fully-approved application. Freeze new credit obligations from the moment you start house hunting.
Add qualifying income. A verifiable part-time job, freelance income with a two-year history, or a co-borrower’s income all raise the denominator and push DTI down.
Target a lower price. The most reliable fix. A $50,000 lower purchase price is roughly $250–$350 less per month — often enough to bring DTI under the lender’s threshold without any lifestyle change.
Calculate Your DTI Now
Use the DTI Calculator to run your exact numbers, or walk through the First-Time Buyer Qualifier to see how DTI fits into your full financial picture alongside credit score, down payment, and loan type.