Debt-to-Income (DTI) Ratio Calculator
Enter your monthly housing payment, all other recurring debt obligations, and your gross monthly income. The calculator instantly computes both your front-end DTI (housing costs only) and back-end DTI (all monthly debts combined), then maps your result against the three standard lender threshold bands — 28/36 conventional, 31/43 FHA/QM, and the 50% expanded non-QM ceiling — so you can see at a glance which loan programs you qualify for.
Back-end DTI
33.33%
Front-end DTI
25.00%
Total monthly debt
$2,000
Conventional eligible
Back-end DTI ≤ 36% — meets standard conforming guidelines.
Your DTI vs lender thresholds (36 / 43 / 50%)
Bars left to right: your DTI · 36% conventional · 43% QM · 50% expanded
Lender threshold comparison
| Program | Front ≤ | Back ≤ | Front | Back |
|---|---|---|---|---|
| Conventional (28/36) | 28% | 36% | Pass | Pass |
| FHA / QM (31/43) | 31% | 43% | Pass | Pass |
| Expanded non-QM (50%) | — | 50% | — | Pass |
This calculator is for educational purposes only and does not constitute mortgage pre-qualification or financial advice.
How it works
Your front-end debt-to-income ratio is the simplest of the two numbers: it divides your monthly housing payment (principal, interest, taxes, and insurance if applicable) by your gross monthly income and expresses the result as a percentage. Conventional conforming lenders typically want this figure at or below 28%. FHA loans allow up to 31%. The front-end ratio isolates the housing burden alone, independent of your other obligations.
Your back-end DTI adds every recurring monthly debt obligation to the housing payment, then divides by gross monthly income. Include car loans, student loans, minimum credit-card payments, personal loans, and any other installment or revolving balances — but not utilities, groceries, subscriptions, or insurance premiums. Conventional conforming guidelines cap the back-end at 36%; the QM (Qualified Mortgage) rule under Dodd-Frank sets the absolute upper limit at 43% for most programs; some non-QM lenders stretch to 50% with compensating factors (high credit score, large reserves, large down payment). Values above 50% exceed all typical maximums.
The threshold comparison surface shows three programs side by side — Conventional, FHA/QM, and Expanded non-QM — with a green or red flag for each DTI dimension. This table is always visible so you can see not only whether you currently qualify for a program, but also exactly how much monthly debt you could add or remove to cross a threshold. Use the result to guide conversations with a lender or mortgage broker; always consult a licensed professional before making borrowing decisions.
Frequently asked questions
What counts as a monthly debt for back-end DTI?+
Include any obligation that appears on your credit report as a required minimum monthly payment: mortgage or rent, car loan, student loan, minimum credit-card payments, personal loans, child support, and alimony. Do not include non-debt living expenses such as utilities, groceries, phone bills, streaming subscriptions, or property and auto insurance — these do not appear in a lender's DTI calculation. If a debt has ten or fewer payments remaining, some lenders may exclude it; ask your lender about their specific policy.
Why is 43% the QM threshold?+
The 43% back-end limit is the ceiling established by the Consumer Financial Protection Bureau (CFPB) for Qualified Mortgages under the Dodd-Frank Act. A QM loan gives the lender a safe harbor against claims that they made a loan the borrower could not afford to repay. Loans above 43% DTI can still be made — they simply fall outside the QM safe harbor and are typically classified as non-QM or 'expanded' loans, usually requiring stronger compensating factors and carrying a higher interest rate.
Does a lower DTI guarantee loan approval?+
No — DTI is one of several underwriting factors. A low DTI is a necessary but not sufficient condition for approval. Lenders also evaluate credit score, loan-to-value ratio, employment history, asset reserves, and the property itself. A borrower with a 30% DTI but a 580 credit score and no reserves may be declined, while a borrower at 43% with a 780 score and six months of reserves may receive excellent terms. This calculator is an educational tool; it does not constitute a mortgage pre-qualification or approval.