The debt service coverage ratio (DSCR) is the primary metric lenders use to evaluate whether an investment property generates sufficient income to support its debt obligations. It is calculated by dividing net operating income (NOI) by total annual debt service (principal plus interest). A DSCR of 1.0 means the property breaks even, while most lenders require 1.20 to 1.50 for approval. Investors should target properties with a DSCR well above the minimum to provide a cushion against vacancy, maintenance surprises, or market downturns.