Debt-to-Income Ratio Calculator — Mortgage Qualification Check
Lenders calculate DTI two ways: front-end (housing only) and back-end (all debt). Enter your income and monthly debts to see both ratios and exactly which loan types you qualify for.
| Item | Monthly Amount | % of Gross Income |
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How Lenders Actually Calculate DTI
Front-end DTI counts only your proposed housing payment (principal, interest, property tax, homeowners insurance, and any HOA dues) divided by gross monthly income. Back-end DTI adds every other recurring debt obligation — auto loans, student loans, minimum credit card payments, personal loans, child support — on top of housing, divided by the same gross income figure. Lenders weight back-end DTI more heavily, since it captures your total monthly obligation, not just the new mortgage payment.
The three major loan categories set different ceilings. Conventional loans (Fannie Mae/Freddie Mac guidelines) generally cap at 36% back-end for the best terms, though many lenders approve up to 45-50% back-end with strong compensating factors (high credit score, large down payment, significant cash reserves). FHA loans allow a higher ceiling — typically up to 43% back-end, sometimes higher with compensating factors, reflecting the program's design for buyers with thinner credit margins. VA loans use a more flexible 41% back-end guideline but weight residual income (what's left after all expenses) more heavily than DTI alone.
Gross income, not take-home pay, is the denominator lenders use — a deliberate standardization, since tax withholding and benefit deductions vary too much person to person to use as a baseline. This means your DTI will always look better on a mortgage application than it might "feel" against your actual paycheck.