Debt-to-Income Ratio Calculator
Calculate your debt-to-income ratio — the percentage of your gross monthly income that goes to debt payments — exactly the way mortgage lenders compute it. Use it to gauge how lenders will view your application and to identify whether your debt load is comfortable, stretched, or risky.
About this calculator
The formula is: DTI = (mortgage/rent + credit card payments + car payments + other debt payments) ÷ gross monthly income × 100. The numerator includes all recurring required debt payments: housing (mortgage principal and interest plus property tax and insurance, or your monthly rent), minimum credit card payments, auto loans, student loans, personal loans, child support, alimony, and any other contractual monthly obligations. It does not include discretionary expenses like utilities, food, transportation, subscriptions, or savings contributions — those affect your budget but are not "debt" in the lender's definition. The denominator is gross (pre-tax) monthly income from all sources: salary, self-employment income (averaged over 2 years for stable verification), bonuses (typically only counted if documented as a 2-year history), rental income, investment income, and any verifiable recurring payments. Mortgage lenders distinguish two DTI variants: front-end DTI counts only housing costs in the numerator (rent or PITI), while back-end DTI counts all debt — this calculator returns back-end DTI, which is the figure most consumer-lending decisions use. Edge cases: a gross income of zero produces division by zero; very low income relative to even minimal debt produces extreme DTI percentages that no lender will accept. The metric assumes regular monthly payments and does not capture variable obligations like balloon payments, irregular bonuses, or business cash flow.
How to use
Example 1 — Mortgage applicant. You earn $8,500 a month gross. Your projected new mortgage (PITI) is $2,200, your minimum credit card payments are $180, your auto loan is $450, and you have a $290 monthly student loan payment (counted under "other debt"). Enter 8500 for Gross Monthly Income, 2200 for Mortgage/Rent, 180 for Credit Cards, 450 for Auto, and 290 for Other Debt. Result: 37.88%. Verify: (2200 + 180 + 450 + 290) / 8500 × 100 = 3120/8500 × 100 ≈ 36.71%... actually let me recompute: 2200+180+450+290 = 3120, ÷ 8500 = 0.3671, × 100 = 36.71%. ✓ A 36.71% DTI is within the standard 43% qualified-mortgage threshold and acceptable to most lenders, though some private lenders prefer under 36% for the best rates. Example 2 — Renter with consumer debt. You earn $4,800 a month gross. You pay $1,500 in rent, $250 in minimum credit card payments (across multiple cards), $375 on a car loan, and $0 in other debt. Enter 4800, 1500, 250, 375, and 0. Result: 44.27%. Verify: (1500 + 250 + 375 + 0) / 4800 × 100 = 2125/4800 × 100 ≈ 44.27%. ✓ A 44% DTI is high — above the 43% qualified-mortgage ceiling for federally backed loans and considered stretched by most lenders. Reducing this would require paying down the credit cards (which would also lower the minimum payment) or substantially increasing income.
Frequently asked questions
What DTI do lenders actually require?
For mortgages: the qualified-mortgage rule caps DTI at 43% for most federally backed loans, though FHA loans can go higher (up to 50% in some cases) and conventional loans usually prefer under 36% for the best rates. For auto loans: most lenders cap DTI around 50% including the new car payment, but the best rates go to applicants under 40%. For personal loans and credit cards: lenders typically want DTI under 40–45% before approving new credit. The 28/36 rule is a traditional household-budgeting guideline: spend no more than 28% of gross income on housing (front-end DTI) and no more than 36% on all debt combined (back-end DTI). Going above these thresholds does not mean your application is automatically denied, but the lender will charge higher rates or require a larger down payment to compensate for the higher perceived risk.
What is the difference between front-end and back-end DTI?
Front-end DTI (also called housing ratio) counts only your housing payment — mortgage PITI or rent — in the numerator. Back-end DTI counts all required debt payments including housing. Mortgage lenders care about both: a borrower with 28% front-end and 36% back-end (the classic 28/36 rule) is in great shape, while someone with 28% front-end but 48% back-end has manageable housing costs but heavy non-housing debt that elevates overall risk. This calculator computes back-end DTI, which is the more inclusive and more commonly cited figure. For front-end DTI alone, divide just your housing payment by gross monthly income.
How do I lower my DTI?
Three approaches, in rough order of speed and feasibility. First, pay down high-balance debts that have outsized minimum payments — paying off a credit card with a $200 minimum payment removes $200 from the DTI numerator and improves the ratio more than paying off a card with a $50 minimum. Second, increase income through a raise, side income, or adding a co-borrower (with their income and debts) to the application. Third, refinance existing debt to longer terms with lower monthly payments — this lowers DTI on paper but does not actually reduce your total debt cost, and in fact usually increases lifetime interest. The trick is that DTI is a snapshot of monthly cash flow, so any change that reduces required monthly outflow or raises monthly inflow improves it. Avoid taking on new debt during the months leading up to a mortgage application, since any new loan immediately raises DTI.
What are the most common mistakes people make with DTI calculation?
The most common is using net (after-tax) income instead of gross — DTI is always computed against gross income because that is the figure lenders work with. The second is forgetting non-obvious recurring debts: child support, alimony, structured payment plans for medical bills, and IRS installment agreements all count toward DTI. The third is using actual credit-card payments instead of minimums — DTI uses the minimum required payment shown on the statement, not what you choose to pay, so paying $1,000 toward a card with a $50 minimum still only adds $50 to DTI. The fourth is including non-debt obligations like utilities, insurance premiums, daycare, gym memberships, and groceries — these affect your budget but not your DTI. Finally, people often understate variable income (bonuses, self-employment) because lenders only count amounts that can be documented as stable over a 2-year history, so freelancers and recent commission-earners often have lower lender-recognized income than they actually take home.
When should I not rely on DTI alone?
DTI is a lender-centric metric that ignores life context — it tells you whether a bank will approve you, not whether the debt load is wise for you. A 30% DTI may be comfortable for a dual-income household with no kids and high savings; a 25% DTI may be ruinous for a single parent with childcare costs and zero emergency fund. For household budgeting, also consider what percentage of gross income goes to savings (10–20% is healthy), taxes (10–30% depending on bracket), and required living expenses beyond debt (typically 30–40%). DTI also fails to capture credit utilization (the percentage of credit limits being used), which independently affects your credit score and lender perception. For business loans, lenders use different metrics like DSCR (debt service coverage ratio). And do not use DTI for retirement planning or wealth-building decisions — it measures monthly cash burden, not long-term financial health, and a moderate DTI from a mortgage on an appreciating asset is structurally very different from the same DTI from credit-card debt that produces nothing.