See the monthly cash flow before you get attached.

Cash flow is the money left over each month after you collect rent and pay every expense, including the mortgage, taxes, insurance, repairs, vacancy, and management. Positive cash flow means the property pays you. Negative cash flow means it costs you money to hold, even if it is appreciating.

Take your monthly rental income, then subtract operating expenses such as taxes, insurance, maintenance, vacancy, and management, and finally subtract the mortgage payment. What remains is your monthly cash flow. The most common mistake is leaving out vacancy and repair reserves.

Many investors target a few hundred dollars of cash flow per unit per month, often cited as around 100 to 300 dollars or more, though the right figure depends on the market, price point, and risk. The number matters less than making sure the calculation includes every real expense.

Usually because the purchase price or loan is too high relative to rent, or because expenses like taxes, insurance, repairs, and vacancy were underestimated. High interest rates and low down payments also squeeze cash flow. Running honest numbers up front is the way to catch this before you buy.