What is debt-to-income ratio and how do you calculate it?

Debt-to-income ratio (DTI) is the percentage of your gross monthly income that goes toward monthly debt payments. You calculate it by dividing your total monthly debt obligations by your gross monthly income. Lenders use it to gauge whether you can afford additional debt.

How to calculate your DTI

Add up all your required monthly debt payments: mortgage or rent, car loans, student loans, minimum credit card payments, personal loan payments, and any other recurring debt obligations. Divide that total by your gross monthly income (before taxes). Multiply by 100 to get a percentage. For example: $1,800 in monthly debt ÷ $5,000 gross monthly income = 0.36, or a 36% DTI. The CFPB defines DTI as your total monthly debt payments divided by your gross monthly income, expressed as a percentage.

What DTI ranges mean to lenders

Below 36% — generally considered manageable; most lenders view this favorably for unsecured credit.
37–43% — the upper boundary for qualified mortgages under traditional lending standards; personal loan lenders may still approve but terms tighten.
44–49% — elevated risk tier; fewer lenders will approve new debt at competitive rates.
50%+ — most lenders view this as overleveraged; approval for new consumer credit becomes difficult.

Front-end vs. back-end DTI

Mortgage lenders often distinguish two DTI calculations. Front-end DTI counts only housing costs (mortgage principal, interest, taxes, insurance) as a share of gross income — lenders typically want this below 28–31%. Back-end DTI ("total DTI") includes all monthly obligations and is the figure most commonly referenced in personal loan underwriting. For personal loans and credit decisions outside of mortgages, lenders almost always focus on the back-end number.

By the numbers

DTI is calculated by dividing total monthly debt payments by gross monthly income. Lenders use this ratio to determine whether you can take on additional debt responsibly. — CFPB
The Federal Reserve tracks household debt service payments as a percentage of disposable personal income at the aggregate level. — Federal Reserve
The CFPB's Ability-to-Repay / Qualified Mortgage rule historically referenced a 43% DTI threshold for qualified mortgages. — CFPB

Key takeaways

DTI = total monthly debt payments ÷ gross monthly income × 100.
Below 36% is the broadly accepted target for consumer creditworthiness; above 43% raises flags for most lenders.
Personal loan lenders focus on back-end DTI (all obligations); mortgage lenders also track front-end DTI for housing costs alone.
Lowering DTI requires either paying down existing debts or increasing gross income — or both.