Calculate your debt-to-income (DTI) ratio and see if you qualify for a mortgage or loan. Get your front-end and back-end DTI ratios vs lender thresholds instantly.
DTI assessment for mortgage & loan qualification
Your debt-to-income ratio is the single most important number mortgage underwriters look at after your credit score. DTI is calculated by dividing total monthly debt payments by gross monthly income. Most conventional lenders want to see a back-end DTI below 43%, and Fannie Mae / Freddie Mac guidelines allow up to 50% with compensating factors. FHA loans — popular with first-time buyers in states like Texas, Florida, and Georgia — accept back-end DTIs up to 57% in some cases. Lenders also look at the front-end ratio, which counts only housing costs (principal, interest, taxes, insurance) and should generally stay under 28%.
A borrower earning $6,000 per month with $500 in existing debts has $1,660 available for housing at the 36% back-end threshold ($2,160 max − $500 existing). That works out to roughly a $250,000 mortgage at 6.5% for 30 years. Reducing monthly debts before applying for a mortgage — paying off a car loan, for example — can dramatically increase your qualifying loan amount. Every $200 per month eliminated from your debt load adds roughly $30,000 to $35,000 in mortgage qualification capacity, depending on your rate and term.
Front-end DTI counts only housing costs and should stay under 28%. Back-end DTI includes all monthly debts and should stay under 43% for conventional loans. Lenders use both to assess mortgage qualification risk.
FHA loans allow front-end DTI up to 31% and back-end DTI up to 43% standard — with certain compensating factors pushing the back-end limit to 57%. FHA is the most flexible option for buyers with higher debt loads.
Conventional loans backed by Fannie Mae and Freddie Mac typically allow back-end DTI up to 45%–50% for well-qualified borrowers. VA loans have no stated maximum DTI but require residual income analysis instead.
Pay off revolving balances, avoid new credit obligations before applying, and consider adding a co-borrower's income. Eliminating a $400/month car payment can add roughly $55,000–$60,000 to your mortgage approval limit.
Debt-to-income ratio is the single number that most often decides a mortgage application. Lenders compute two: the front-end ratio covers housing costs alone, and the back-end ratio adds every other monthly debt obligation. Both use gross income, not take-home — a distinction that makes the ratio look better than the household budget feels. Conventional underwriting generally wants the back-end ratio at or below 43%, with automated systems stretching to around 50% where credit and reserves are strong. Crucially, only debt payments count: utilities, insurance, groceries and childcare are invisible to the calculation.
Front-end DTI = (Housing payment ÷ Gross monthly income) × 100Back-end DTI = (Total monthly debt payments ÷ Gross monthly income) × 100where:
Assumptions: Uses gross income and minimum required payments, not what you actually pay. Debts with fewer than roughly ten payments remaining are often excluded, which is why clearing a nearly-finished car loan sometimes changes nothing.
Gross income of $8,000 a month, a proposed $2,300 housing payment, plus existing debts.
ResultFront-end 28.75%, back-end 40.9% — qualifies under the 43% rule
Paying off the card balances entirely removes $140 and drops the ratio to 39.1%, buying roughly $310 a month of additional borrowing capacity — often more valuable at application time than the same cash added to the down payment.