Debt-to-Income Ratio Calculator

Your debt-to-income ratio is the number a loan officer looks at before anything else — not your credit score, not your savings: can your income carry your required monthly payments? DTI is total monthly debt payments divided by gross monthly income. Enter your income before tax and each required payment (housing, autos, card minimums, student loans, other obligations), and this calculator gives you both ratios the industry uses plus a verdict.

There are two DTIs. The front-end ratio counts only housing — mortgage or rent, plus property taxes and insurance — and the traditional guideline says keep it under 28%. The back-end counts every debt payment and should stay under 36%, with 43% being the qualified-mortgage line most conventional lenders enforce and 50% the practical hard cap even with strong compensating factors. The defaults show a typical borderline case: $6,000 gross income carrying $2,300 of payments — 38.33% back-end, 25.00% front-end.

What counts as a payment surprises people. For credit cards, lenders use the minimum shown on your statement — not what you actually pay, and never the full balance — so even a card you clear every month still contributes its minimum to the ratio. Child support and alimony count as debts. Variable income — overtime, bonuses, commissions, side-gig earnings — generally needs a two-year documented history before an underwriter will count it, and self-employed borrowers should expect to show two years of returns.

Improving DTI is refreshingly mechanical: remove a payment or raise income. Paying off a small installment loan removes its entire monthly obligation from the numerator — the single fastest lever. Snowballing a card balance down shrinks its minimum. On the income side, documented raises, bonuses with history, or a co-borrower’s income all help. Planning an attack? Our debt payoff calculator shows which balance dies fastest, and the paycheck calculator shows what a raise really nets after tax.

Where does your target need to be? For a conventional mortgage, under 36% back-end is comfortable and 43% is the usual QM ceiling; FHA and some portfolio lenders stretch to 45-50% with strong credit and reserves. The 28/36 rule still frames home affordability: front-end 28%, back-end 36%. Model the mortgage side directly — principal, interest, taxes and insurance — with our mortgage calculator, and remember the housing payment you enter here must be the full PITI number, not just principal and interest.