Debt-to-Income Ratio (DTI)
The share of your gross monthly income that goes to debt payments.
Also called: debt to income
Lenders use DTI to gauge how much new debt you can carry. The 'front-end' DTI counts only housing costs (PITI). The 'back-end' DTI adds car loans, student loans, credit-card minimums, and other recurring debt.
Conventional mortgage underwriting typically caps back-end DTI around 43%. FHA loans allow more.
DTI is a snapshot — it doesn't see your savings rate or your discretionary spending. A low DTI doesn't mean a payment is comfortable, only that lenders consider it within range.