Comprehensive Guide
Learn more in our Planning Guide.
How it works
Debt-to-income ratio is the number lenders actually underwrite, and it is simpler than most people expect: total monthly debt payments divided by gross monthly income, before taxes. The calculator adds the payments that count — housing (rent or the full mortgage payment with taxes and insurance), auto loans, minimum credit card payments, and other obligations like student loans and child support — then divides by gross income. What does not count: utilities, groceries, subscriptions and insurance premiums, because they are expenses, not debts. The thresholds come straight from mortgage underwriting. At or below 36%, lenders see a comfortable borrower with room to absorb surprises. Between 36% and 43% is fair — approvals still happen, but terms tighten and compensating factors start to matter. Above 43% is the ceiling for most qualified mortgages, where borrowing more becomes difficult and every rate shock lands directly on the household budget. Two levers move the ratio, and the calculator makes both visible: paying down debts removes payments from the numerator, and raising income grows the denominator. A loan payoff that deletes a $420 payment improves DTI exactly as much as a $5,800 raise — which is why the cheapest way to qualify for a mortgage is often retiring a car loan first.Formula
DTI = (housing + auto + cards + other monthly debt) / gross monthly income x 100
Tips
- Lenders count the full housing payment — principal, interest, taxes and insurance — not just the loan.
- Only minimum required card payments count, but paying cards in full monthly keeps them at zero.
- Paying off a small loan is the fastest DTI fix — deleting a $420 payment beats a $5,800 raise.
- Gross income is before taxes; do not use take-home or you will overstate the ratio.
- Recompute after every debt payoff — the drop is often larger than expected.