About this calculator
DTI is a fraction: monthly debt payments divided by gross monthly income. Lenders compute two versions. The front-end (housing) ratio counts only the home — for a purchase, principal, interest, property tax, homeowners insurance, HOA dues and any mortgage insurance. The back-end (total) ratio adds every recurring debt that shows on your credit report: car loans and leases, student loans, credit-card minimum payments, personal loans, and court-ordered support. On $120,000 of income ($10,000 a month), a $2,400 housing payment is a 24% front-end ratio; add $1,000 of other debts and the back-end ratio is 34%.
The benchmarks in the table are conventions from the agencies' underwriting guides, not laws — automated underwriting weighs credit, reserves and LTV alongside DTI every day. Conventional loans (Fannie Mae/Freddie Mac) are routinely approved to a 45% back-end ratio and can reach 50% with strong compensating factors. FHA uses 31%/43% as its no-questions benchmarks and allows up to roughly 47%/57% when compensating factors (reserves, residual income, minimal payment increase) are documented. VA publishes a 41% back-end guideline but actually decides on residual income — the cash left after all obligations — which is why VA files above 41% are approved every day. Treat a ratio above your program's stretch limit as a planning signal: pay down the debt with the largest monthly payment, not necessarily the largest balance, to move the ratio fastest.
How to use it
- Enter combined gross annual income for everyone who will be on the loan.
- Enter the housing payment you have now (rent) or the full PITI + HOA of the home you are targeting.
- Add each monthly debt payment as it appears on your credit report — for credit cards, the minimum payment, not the balance.
- Compare both ratios against the program rows in the table; the "debt room left" results show how much more monthly payment fits under a 45% or 50% cap.
The formula
Income is gross — before tax — because underwriting guidelines are written that way; a $120,000 salary counts as $10,000 a month even though take-home is nearer $7,500. Only recurring, documented obligations count as debts: revolving and installment payments on the credit report, support obligations, and the full housing cost. Day-to-day living costs (utilities, food, insurance premiums) are excluded, which is why lenders separately sanity-check residual income on VA loans.
Worked example
Income $120,000 a year, housing $2,400 a month, a $450 car payment, $350 of student loans and $200 of card minimums: front-end DTI is 24.0%, back-end is 34.0%. That file is inside every mainstream benchmark — the classic 28/36 rule included — and has $1,100 a month of debt room before it touches a 45% conventional cap. Add a $700 second-car payment and the back-end ratio jumps to 41%: still workable for FHA and VA, but conventional approval now leans on credit score and reserves.
Sources: Benchmark conventions: Fannie Mae Selling Guide B3-6-02 (50% DU ceiling), Freddie Mac manual-underwriting guides, HUD 4000.1 FHA ratios (31/43 manual, ~47/57 TOTAL Scorecard stretch) and the VA 41% guideline (VA Pamphlet 26-7). Benchmarks are conventions, not guarantees. Last updated: October 2026.
Frequently asked questions
What DTI do I need for a conventional mortgage?
Fannie Mae's underwriting engine routinely approves back-end ratios up to 45%, and up to 50% for strong files (high credit score, large reserves, low LTV). The old 28/36 rule is a conservative guideline, not a cap. Above 50%, a conventional approval is exceptional — FHA (to ~57% with compensating factors) or paying down debts are the realistic paths.
Do lenders use gross or net income for DTI?
Gross — your income before tax and deductions, documented with pay stubs, W-2s and tax returns. It flatters the ratio compared with your lived budget, which is one reason housing counsellors suggest keeping your own back-end calculation on take-home pay under roughly 40% as well.
What counts as a debt in DTI?
Payments that appear on your credit report or are legally ordered: auto loans/leases, student loans (using the documented payment or a formula percentage of the balance on income-driven plans), credit-card minimums, personal loans, alimony and child support, and timeshare or land payments. Utilities, subscriptions, insurance and taxes on their own do not count.
How can I lower my DTI fastest?
DTI moves with monthly payments, not balances — so eliminating a $450 car payment entirely lowers the ratio more than paying $10,000 off a card whose minimum barely changes. Small installment loans with fewer than 10 payments left are sometimes excluded by underwriters; ask. Avoid taking on any new monthly payment in the months before applying.
What is residual income and why does VA care?
Residual income is what is left each month after debts, taxes, housing costs and an estimated maintenance/utilities charge. The VA publishes minimum residual-income tables by region and family size and weighs them alongside its 41% DTI guideline — a file at 48% DTI with strong residual income can pass where a 39% file with none left over fails.
What formula does this dti calculator use?
Front-end DTI = housing payment ÷ gross monthly income. Back-end DTI = (housing + all monthly debt payments) ÷ gross monthly income. Income is gross — before tax — because underwriting guidelines are written that way; a $120,000 salary counts as $10,000 a month even though take-home is nearer $7,500. Only recurring, documented obligations count as debts: revolving and installment payments on the credit report, support obligations, and the full housing cost. Day-to-day living costs (utilities, food, insurance premiums) are excluded, which is why lenders separately sanity-check residual income on VA loans. The worked example on this page applies the formula step by step with real numbers, so you can verify the result by hand.