The Golden Ratio: A Simple Formula for Rental Cash Flow The Golden Ratio: A Simple Formula for Rental Cash Flow Stop "feeling" like a deal is good and start "knowing" it is. Master the math that separates successful investors from the rest. The Problem: The "Gross Income" Illusion Many first-time investors look at a rental property and see only the monthly rent check. They assume that if the rent is $2,000 and the mortgage is $1,500, they are making $500 a month. This is a dangerous trap. By ignoring "invisible" expenses like capital expenditures, vacancy rates, and maintenance, you could actually be losing money every month without realizing it until it's too late. The Rookie Mistake: Failing to set aside a "Reserve Fund" for big-ticket repairs like roofs or HVAC systems. These aren't monthly bills, but they are inevitable c...