How This Debt-to-Income Calculator Works
Front-end DTI = housing payment ÷ gross monthly income. Back-end DTI = (housing payment + all other required monthly debt payments) ÷ gross monthly income. Gross means before tax. The traditional lender guidance is 28% front-end and 36% back-end, though many lenders accept back-end ratios up to 43% — and some mortgage programs go higher with compensating strengths like a large down payment or cash reserves.
Front-end = housing ÷ income · Back-end = (housing + other debts) ÷ incomeIncome is gross (before tax). Traditional guidance: 28% front-end, 36% back-end. Many lenders accept up to 43% back-end.
Worked example: gross income $6,000 a month, housing payment $1,500, other debts $600. Front-end = $1,500 ÷ $6,000 = 25.0%. Back-end = ($1,500 + $600) ÷ $6,000 = 35.0% — inside both the 28% and 36% guidance figures.
Practical tips
Lenders use pre-tax income. Using take-home pay makes your ratios look worse than the lender's version and can mislead you into a smaller house than you qualify for.
For credit cards, lenders generally use the minimum monthly payment, not the balance. Paying a card down helps your ratio only when the required minimum falls.
Passing at 36% does not mean the payment is comfortable — taxes, insurance, food, transport and savings all come out of the same income. Run the payment through a full budget too.
Paying off a $300-a-month car loan cuts your back-end ratio by 5 points on $6,000 of income — often the fastest route to qualifying.