Calculateur d'accessibilité du prêt

The 28/36 rule is an industry guideline that says your monthly housing costs should not exceed 28% of your gross monthly income (front-end DTI), and your total monthly debt payments including housing should not exceed 36% of your gross income (back-end DTI). For example, if you earn $6,000 per month, your housing payment should stay under $1,680 and your total debts under $2,160. Many lenders use this as a baseline, though some allow higher ratios for borrowers with strong credit.

Front-end DTI (also called housing ratio) measures only your housing costs against your gross income. It includes your mortgage payment, property taxes, insurance, and HOA fees. Back-end DTI (also called total debt ratio) includes all monthly debt obligations: housing costs plus car payments, student loans, credit card minimums, and any other recurring debts. Lenders look at both ratios when evaluating your loan application, with the back-end DTI typically being the more important factor.

Interest rate has a significant impact on your maximum affordable loan. A higher rate means more of your monthly payment goes toward interest, leaving less for principal, which reduces the total amount you can borrow. For example, at 6% on a 30-year mortgage with a $1,500 monthly payment, you could borrow about $250,000. At 8%, that same payment only supports about $204,000 in borrowing. The sensitivity table in this calculator shows exactly how rate changes affect your specific situation.

DTI calculations use gross monthly income, which is your total income before taxes and deductions. This is the standard used by virtually all lenders. Your gross income is higher than your take-home pay, so your DTI ratio will appear lower than if calculated with net income. While lenders use gross income for qualification, it is wise to also consider your actual take-home pay when deciding how much debt you are comfortable carrying.