Qu'est-ce que PITI ?

PITI stands for Principal, Interest, Taxes, and Insurance, and represents the full monthly housing payment that lenders evaluate when determining mortgage affordability. Each component serves a distinct purpose. Principal is the portion of your payment that reduces the outstanding loan balance. Interest is the cost charged by the lender for borrowing the money. Taxes refer to property taxes, which are collected monthly by the lender and held in escrow until the annual tax bill is due. Insurance includes homeowners insurance and, if applicable, private mortgage insurance (PMI) for borrowers who put down less than 20%.

Lenders use PITI to calculate two key affordability ratios. The front-end ratio (also called the housing ratio) divides your monthly PITI by your gross monthly income; most conventional lenders prefer this to stay below 28%. The back-end ratio (debt-to-income ratio or DTI) adds all monthly debt obligations to PITI and divides by gross income; most lenders prefer a back-end DTI below 43%, though FHA loans allow up to 57% in some cases.

Understanding PITI is important because buyers often focus solely on purchase price or even just the principal and interest portion of a payment when estimating affordability. Property taxes and insurance can add hundreds of dollars per month to the actual payment. In high-tax states or areas with elevated insurance premiums (such as coastal or wildfire-prone regions), the T and I portions of PITI can add 30% to 50% to the principal-and-interest payment.