Debt-to-Income Calculator
Compute the two ratios mortgage underwriters check first: front-end DTI (housing ÷ gross income) and back-end DTI (housing + all debts ÷ gross income), read against the standard 36% / 43% guideline bands.
Your DTI ratios
Example: $10,000/mo income, $2,500 housing, $800 debts → 33% back-end.
Why lenders look at two ratios
The front-end ratio isolates housing; the back-end adds every other recurring debt. In the worked example — $10,000 gross monthly income, $2,500 of housing, $800 of other payments — the front-end is 25% and the back-end is 33%: comfortable. Underwriters weight the back-end more, because it captures the whole claim on your income. These figures come from the same tested engine as the calculator above.
Reading the bands
At or under 36% is comfortable conventional territory; 37–43% is approvable but tight (43% is the traditional underwriting line, formerly the qualified-mortgage cap); 44–50% requires strong compensating factors; above 50%, options narrow sharply. DTI is also the lever behind affordability math — the House Affordability Calculator works these same ratios backwards into a maximum home price.
Frequently asked questions
What counts as debt in the back-end ratio?
Recurring monthly obligations: your housing payment, car loans, student loans, personal loans, credit-card minimums, and court-ordered payments like child support (which lenders count from the court order — it does not appear on credit reports). Utilities, groceries, subscriptions, and premiums like auto or health insurance do not count; homeowners insurance is already inside a PITI housing payment.
Is income gross or take-home?
Gross — before taxes and deductions. Lenders compute DTI on gross monthly income, which is why the ratios look more forgiving than your take-home budget feels.
What DTI do I need for a mortgage?
Conventional guidelines prefer 36% or less on the back end; 43% is the traditional underwriting benchmark (it was the qualified-mortgage cap until regulators replaced it with a price-based test in 2021), and automated approvals can stretch toward 50% with strong compensating factors (credit, reserves, down payment). Lower is always stronger.
How do I lower my DTI?
Pay off or pay down monthly obligations (eliminating a car payment or a card minimum removes its full amount from the ratio), avoid new credit before applying, and where legitimate, document additional income. Small debts with high minimums are the most efficient targets.
Not financial advice: a general educational estimate. Loan programs define countable income and debts in detail, and lender overlays vary — a pre-approval is the authoritative answer. Values are processed locally in your browser and never transmitted. See the methodology page.