DTI Ratio Calculator

Debt-to-income ratio (DTI) is the share of your gross monthly income that goes toward required debt payments. It is the single most important affordability metric in mortgage, auto, and personal loan underwriting — a direct read on whether you can absorb a new payment without financial strain.

DTI answers a simple question: of every dollar you earn before taxes, how many cents are already promised to lenders? The lower the number, the more room in your budget for savings, emergencies, and a new loan payment.

Enter your annual income sources (salary, pension, investment, other) and your monthly recurring debt payments (rent or mortgage, credit cards, auto loans, student loans, and other fixed debts). The calculator normalizes income to monthly, sums both sides, and divides total debt payments by gross income to produce your back-end DTI as a percentage.

For the most accurate read, use the minimum payment on each credit card (not the full balance) and the actual monthly installment — not interest-only or deferred amounts — for each loan. Exclude utilities, insurance, and subscriptions: lenders do not count them.

DTI = total_debt_payments / gross_monthly_income

Multiply by 100 to express it as a percentage. Sum every required monthly debt payment in the numerator. Convert annual income to monthly (divide by 12) for the denominator. If you have multiple income streams, add them before dividing.

A borrower earns $6,000 gross per month ($72,000 per year) and carries the following monthly obligations:

Back-end DTI = 2,300 / 6,000 = 0.3833 → 38.3%
Front-end DTI = 1,500 / 6,000 = 0.2500 → 25.0%

A 38.3% back-end DTI fits inside conventional limits with compensating factors and well inside FHA's 43% cap. The 25% front-end ratio is comfortably below the 28% rule of thumb, so the housing payment itself is not stretching the budget.

The two ratios answer different underwriting questions. Front-end isolates housing affordability; back-end measures total debt burden. Mortgage lenders usually publish both caps, and the loan must clear both.

Limits move with the market. Conforming loans currently tolerate DTIs into the high 40s when automated underwriting returns an approve/eligible and the borrower has reserves, a strong FICO, and stable employment.

Sample back-end DTI at a constant $6,000 gross monthly income — demonstrating how quickly additional debt tightens the ratio:

DTI is a ratio, so you can improve it from either side — raise income or lower required payments. Payment-side moves act immediately; income-side moves usually need a two-year history before a lender will count them.

Using full credit card balances instead of minimums. Lenders count the minimum payment shown on your credit report, not the balance — so a $10,000 balance with a $200 minimum only adds $200 to DTI.

Forgetting property tax and insurance. Front-end DTI includes the full PITI payment. Using principal and interest alone understates the housing ratio by 20–35% in high-tax states.

Counting net income. Personal budgeting uses take-home pay, but every mortgage program uses gross. Using net makes your self-calculated DTI look higher than what the lender will see.

Ignoring non-applicant debts in community-property states. In AZ, CA, ID, LA, NV, NM, TX, WA, and WI, FHA and VA underwriters may count a spouse's debts even if the spouse is not on the loan.

What is the difference between front-end and back-end DTI?

Front-end DTI (also called the housing ratio) divides only housing costs — mortgage principal, interest, taxes, and insurance (PITI) plus HOA — by gross monthly income. Back-end DTI adds every other recurring debt: auto loans, credit card minimums, student loans, personal loans, and court-ordered payments. Lenders evaluate both, but back-end is the headline number on most approval decisions.

What DTI limits do lenders typically require?

Conventional conforming loans generally cap back-end DTI at 43–45% with strong compensating factors pushing it to 50%. FHA loans allow 31% front-end and 43% back-end, extending to 50%+ with residual income. VA loans use 41% back-end plus a residual income test. USDA loans require 29% front-end and 41% back-end. DSCR investor loans ignore personal DTI entirely and underwrite to property cash flow instead.

How does DTI affect mortgage approval?

DTI is one of the top three underwriting factors alongside credit score and down payment. A lower DTI proves you can absorb the new mortgage payment without stretching your budget. Borrowers under 36% generally see the best rates and fewest conditions; between 36% and 43% you still qualify but may face rate add-ons; above 45% you will need compensating factors like reserves, a larger down payment, or a non-QM program.

Which debts are excluded from DTI calculations?

Lenders exclude recurring household expenses that are not credit obligations: utilities, cell phone, internet, groceries, gasoline, health insurance premiums, and most subscription services. Homeowners insurance and property tax are only counted inside the housing payment (front-end). Installment debts with fewer than 10 remaining payments are often omitted at the underwriter's discretion if the payment is not significant.

How can I lower my DTI quickly before applying for a loan?

Pay down revolving balances first because credit card minimums are calculated from the balance — wiping a card clears its DTI contribution. Pay off any installment loan with fewer than 10 payments left. Avoid new loans or credit inquiries in the 60–90 days before application. If possible, add a co-borrower with income or document side income (bonuses, part-time work) that has a two-year history on tax returns.

Does DTI use gross or net income?

Mortgage DTI uses gross (pre-tax) monthly income. That includes base salary, overtime and bonuses with a two-year average, self-employment net profit from Schedule C, pension, Social Security, and documented rental income. Net (take-home) income is only used in personal budgeting DTI, which is stricter because it reflects cash flow after taxes and 401(k) contributions.

How does adding a co-borrower change DTI?

A co-borrower's income is added to the numerator's denominator (gross income) and their debts are added to the numerator (monthly obligations). If their income-to-debt profile is stronger than yours, the combined DTI drops; if they bring more debt than income, it rises. Non-occupant co-borrowers are allowed on FHA and some conventional loans but tighten the maximum DTI the program permits.