Debt-to-Income Calculator

Last updated July 2, 2026

Debt-to-income ratio is the number lenders use to assess whether a borrower can afford additional debt, and it's also one of the most useful self-assessment tools in personal finance. The calculation divides total monthly debt payments by gross monthly income and expresses the result as a percentage. A household with $4,200 in monthly gross income and $1,200 in monthly debt payments has a 28.6 percent DTI. Mortgage lenders use two variants: the front-end ratio, which measures only housing costs against income, and the back-end ratio, which includes all recurring debt. The conventional mortgage guidelines recommend a front-end ratio no higher than 28 percent and a back-end ratio no higher than 36 percent, though lenders frequently approve loans at higher ratios for borrowers with strong compensating factors.

The 36 percent back-end threshold is more than a lending standard — it functions as a practical financial health benchmark. At 36 percent DTI, a household is allocating more than one-third of its gross income to debt payments before taxes, housing utilities, food, and other expenses. For a family earning $80,000 gross ($6,667 per month), a 36 percent DTI means $2,400 per month in debt payments, leaving approximately $3,200 gross — perhaps $2,400 after taxes and FICA — for everything else. That budget is thin in most markets and leaves very little room for savings or unexpected expenses. Lenders who approve at 43 to 50 percent DTI are extending loans to borrowers who, under normal budget analysis, are financially stretched.

The calculation shows your current back-end DTI — total monthly debt payments divided by gross monthly income. Below 36 percent is comfortable; 36 to 43 percent is manageable but tight; above 43 percent warrants serious attention to debt reduction before taking on additional obligations. Use the DTI calculation to evaluate how any new debt — mortgage, car, credit card — would affect your ratio before committing.