DTI Calculator (Debt-to-Income)
The two ratios every lender computes: housing alone against income (front-end) and all debts against income (back-end), set against the classic 28/36 benchmarks — labeled as benchmarks, not laws.
The ratios a lender computes before your name
Debt-to-income comes in two flavors. The front-end ratio is housing alone against gross income; the back-end ratio adds every other debt payment. Underwriting tradition benchmarks them at 28% and 36% — the 28/36 rule — though modern approvals often stretch the back ratio into the 40s.
Front = housing ÷ gross monthly income · Back = (housing + other debt payments) ÷ gross monthly income
Example: $8,000 gross monthly income, $2,080 of housing, $1,050 of other payments: front ratio 26.00% (inside 28), back ratio 39.13% (past the classic 36) — a borrower the old rule declines and a modern lender may well approve. Both readings are shown, labeled.
Benchmarks are weather, not law
The 28/36 figures descend from mid-century underwriting manuals. They survive because they correlate with loans performing — not because a household at 37% is in danger or one at 27% is safe. Your own budget, with its childcare, commuting and food realities, is the truer instrument; DTI is the lender's, and this page shows you their instrument so no quote surprises you.
How this is calculated
Plain division on the figures you enter, gross income as specified (before tax — the lender convention). Housing should include taxes, insurance and HOA for mortgage purposes (the PITI figure); other debts are the minimum/contractual monthly payments as they appear on a credit report. The benchmarks are displayed as labeled tradition, not thresholds this site endorses.
Frequently asked questions
Which debts count in the back-end ratio?
Payments appearing on the credit report: auto and student loans, card minimums, personal loans, child support obligations. Living expenses — utilities, groceries, subscriptions — do not count in the lender's version, however real they are.
Can a high DTI be offset?
Yes — lenders weigh compensating factors: large reserves, excellent credit, low LTV, residual income (the VA formalizes this). DTI is a gate with a human and algorithmic appeals process, not a wall.
Front ratio uses rent or mortgage?
Whichever housing payment you carry or propose. When qualifying for a mortgage, the proposed PITI + HOA is used — which is why the PITI calculator and this one pair naturally.
Is gross income really the base? It feels wrong.
It is the industry base, and yes — it flatters everyone equally, which is why approved-at-45% borrowers can still feel squeezed: their real denominator was take-home pay all along.
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