What does debt-to-income ratio measure?
Debt-to-income ratio, or DTI, compares monthly debt obligations with the monthly income the lender accepts for qualification. It is usually expressed as a percentage. The calculation includes the proposed housing payment and other counted debts. It helps evaluate repayment capacity, but it does not describe every expense in your household budget.
A hypothetical DTI calculation
Suppose accepted gross monthly income is $8,000, the proposed qualifying housing payment is $2,400, and other counted monthly debts total $800. The calculation is $3,200 ÷ $8,000 = 40%. These are invented educational figures, not an approval threshold or a statement that this payment would fit your life.
Why the lender’s number may differ
Gross income is generally income before taxes and deductions, not take-home pay. Qualifying income can differ from deposits or a recent paycheck. Student loans, revolving accounts and other obligations have program-specific treatment. There is no single DTI limit that establishes eligibility for every mortgage.
Bring the calculation back to your budget
Ask which income and debts were included, and confirm that the housing payment accounts for applicable taxes, insurance and association charges. Then compare the result with your actual take-home budget, including food, utilities, transportation, care costs and savings. A qualifying result and a comfortable payment are separate questions.