The ratio lenders check first. See where you stand and how much room you have.
A debt-to-income (DTI) calculator shows the ratio lenders check first when you apply for a mortgage or loan. It compares your monthly debt payments to your gross monthly income, and tells you where you stand and how much room you have.
Debt-to-income is the clearest signal of whether you can take on a new payment. Two ratios matter: the front-end (housing only) and the back-end (all debt). Most mortgage programs want the back-end at or below 36-43%, though some allow more with strong credit and reserves. A high DTI doesn't just risk denial, it usually means a smaller loan or a higher rate.
You can move DTI two ways: lower the top (pay down monthly debts, cards and car loans have the biggest effect) or raise the bottom (increase documented income). Even eliminating one small fixed loan payment can shift your ratio enough to change what you qualify for, because DTI is based on required monthly payments.
Your debt-to-income ratio (DTI) is your total monthly debt payments divided by your gross monthly income, and lenders use it to judge whether you can take on more debt. For a mortgage, many lenders look for a back-end DTI at or below 36%, though some programs allow higher with strong credit and reserves. A lower DTI signals more breathing room and often unlocks better terms. Knowing your ratio before you apply tells you where you stand and how much room you have.
Lenders actually look at two ratios. The front-end (or housing) ratio counts only your housing payment against income, and is often capped near 28%. The back-end ratio counts all debt, housing plus cars, student loans, and minimum card payments, and is usually capped near 36% to 43% depending on the loan. The back-end ratio is the one that most often limits how much you can borrow, because it captures your full obligations rather than housing alone.
Because DTI is a ratio, you improve it by either reducing monthly debt or increasing income. Paying down or eliminating a card or a small loan removes its payment from the numerator and can move the ratio quickly. Avoiding new debt before a mortgage application keeps the ratio steady, and raising income, a raise, a second job, or documented side income, helps the denominator. Even paying off one nagging installment loan can be the difference between approval and denial.
Of all the places DTI is used, mortgages weigh it most heavily, because the loan is large and long. A high DTI signals that a new housing payment could strain your budget, so lenders either decline or require compensating factors like a big down payment or cash reserves. Managing your DTI in the months before applying, by holding off on new car loans or large card balances, can materially improve both your approval odds and your rate.
DTI is easy to confuse with credit utilization, but they measure different things. DTI compares your monthly debt payments to your income; utilization compares your card balances to your credit limits and is a major factor in your credit score. You can have low utilization but high DTI, or vice versa. Lenders look at both: utilization feeds your score, while DTI gauges cash-flow capacity. Keeping both low puts you in the strongest position to borrow.
Different loans allow different debt-to-income ceilings, so knowing the limits helps you target the right program. Conventional mortgages often prefer a back-end DTI at or below 36%, though automated underwriting can approve higher ratios, sometimes to 45% or beyond, for borrowers with strong credit and cash reserves. FHA loans are more flexible, frequently allowing back-end ratios into the mid-40s or higher with compensating factors, which helps buyers with more debt. VA loans focus heavily on residual income, the cash left after all obligations, alongside DTI. Auto and personal lenders use DTI too but weigh it less rigidly than mortgage lenders. Because the thresholds vary, a ratio that is too high for one program may still qualify for another. If your DTI sits near a limit, a lender can tell you which loan types fit and what paying down a single debt would do to your eligibility.
Lenders generally like a back-end DTI at or below 36%, and often allow up to 43-45% for qualified mortgages. Lower is better.
Divide your total monthly debt payments (including housing) by your gross monthly income. This calculator does it and shows both front-end and back-end ratios.
Gross, your income before taxes and deductions.
Many lenders prefer a back-end DTI at or below 36%, with some mortgage programs allowing up to 43% or higher for strong borrowers. Lower is better; it signals more room in your budget and often earns better terms.
No, DTI is not part of your credit score, which uses credit utilization instead. But lenders check DTI separately when you apply for a loan, so both matter for getting approved.
See the exact formula and a worked example on our methodology page.