See if you qualify for a mortgage
Front-end & back-end DTI, instantly.
Enter your gross monthly income (before taxes) and each of your recurring monthly debt payments. The calculator returns two numbers lenders care about: your front-end ratio (housing cost as a percentage of income) and your back-end ratio (all debt payments as a percentage of income). The back-end ratio is the one mortgage lenders weigh most heavily.
Your debt-to-income ratio is one of the clearest signals of financial breathing room. A lower ratio means more of your income is free for saving, investing, and handling surprises. Lenders use it to judge how safely you can take on a new loan.
Because DTI is a ratio, you improve it by lowering debt payments or raising income. The fastest win is usually eliminating a whole payment — paying off a car loan or a small personal loan removes that payment entirely from the numerator, which often moves your ratio more than chipping away at several balances at once. Avoid taking on new debt (a new car, financed furniture) in the months before applying for a mortgage.
Debt-to-income ratio is deliberately simple arithmetic, which is part of why lenders rely on it so heavily — there is nothing to interpret or argue about:
DTI = (Total monthly debt payments ÷ Gross monthly income) × 100
Two details decide whether your number is accurate. First, income is gross — the figure before tax and deductions, not what lands in your account. Second, only debt obligations count in the numerator: mortgage or rent, car loans, student loans, personal loans, and the minimum payments on credit cards. Utilities, groceries, insurance, phone bills, and subscriptions are living costs, not debts, and lenders leave them out entirely.
Worked example: someone earning $7,000 gross per month with a $1,800 housing payment, a $400 car loan, $250 in student loans, and $150 in card minimums has $2,600 in monthly debt. That is $2,600 ÷ $7,000 = 0.371, or a 37.1% back-end DTI — acceptable to most lenders, but without much slack.
A credit score describes how reliably you have repaid debt in the past. DTI describes whether you can plausibly afford the next one. The two answer different questions, which is why a borrower with an excellent score can still be declined: if 55% of gross income is already committed to debt, past reliability does not create room for another payment.
Regulators reinforced this after the 2008 housing crisis. The Ability-to-Repay rule requires lenders to verify that a borrower can realistically afford a mortgage, and DTI is the primary evidence. That is why the 43% threshold appears so often — it has been a common ceiling for qualified mortgages, though several programs allow higher with compensating factors like large reserves or a strong credit profile.
It is worth reading your DTI as a personal metric rather than a lending hurdle. It tells you what share of your earnings is already spoken for before you have bought food or saved anything. At 20% you have genuine flexibility. At 36% you are comfortable but should be cautious about adding obligations. Above 43%, a single unexpected expense — a car repair, a medical bill, a month of reduced hours — has to go on credit, which raises the ratio further. That feedback loop is how manageable debt becomes unmanageable debt.
Because it is a ratio, only two levers exist: reduce the numerator or raise the denominator.
The front-end ratio isolates housing alone against gross income; the back-end includes every debt. Lenders look at both because they describe different risks. A borrower at 25% front-end but 48% back-end can afford the house itself but is carrying heavy consumer debt alongside it. A borrower at 33% front-end and 35% back-end has an expensive home but almost nothing else — a different and often safer profile. The traditional guideline pairs them as 28% front-end and 36% back-end.
A back-end DTI at or below 36% is considered good and qualifies for most mortgages. Up to 43% is often still acceptable, and some programs allow up to 50%, but higher ratios leave less financial cushion.
Front-end DTI counts only your housing payment against gross income. Back-end DTI counts all monthly debt (housing plus car, student loans, and credit card minimums). Lenders focus on the back-end ratio.
Lenders use gross (pre-tax) income. When budgeting for real life, though, it's wise to check your payments against your take-home pay too, since a ratio that looks fine on gross income can feel much tighter on net.
Your rent or mortgage payment counts. Utilities, groceries, insurance, and other living expenses are not part of the DTI ratio — only debt obligations are.