How Much Cash Flow Should a Rental Property Generate?

Cash flow — the money left over each month after collecting rent and paying every expense, including the mortgage — is what actually lands in your pocket, as distinct from paper metrics like cap rate or ROI. How much is "enough" depends on your goals and risk tolerance, but there are common benchmarks worth knowing.

A common per-unit benchmark

Many investors target at least $100-$300 in positive monthly cash flow per unit as a baseline, after accounting for the mortgage, taxes, insurance, an allowance for vacancy, and an allowance for maintenance/capital expenses — not just the obvious recurring bills. Some investors in higher-cost markets accept thinner per-unit cash flow in exchange for stronger appreciation, while investors focused purely on cash flow often look toward lower-cost markets specifically to hit a higher per-unit number.

Don't forget the expenses that don't happen every month

A property can look cash-flow-positive on paper while actually losing money once you account for costs that hit irregularly rather than monthly: a new roof, HVAC replacement, a major appliance failure. A common practice is setting aside roughly 5-10% of monthly rent into a maintenance/capital expense reserve specifically for these irregular costs, treating it as a real expense in your cash flow calculation rather than a surprise when it happens.

Account for realistic vacancy, not zero vacancy

Calculating cash flow assuming the unit is rented 100% of the time, every year, overstates your real return. Build in a vacancy allowance (commonly 5-8% of annual rent, though this varies by market and how quickly units typically re-rent in your area) so your cash flow number reflects reality rather than an unrealistic best case.

The 50% rule as a rough sanity check

A widely used (if imprecise) rule of thumb: assume roughly 50% of gross rental income will go toward operating expenses (excluding the mortgage) — taxes, insurance, maintenance, vacancy, and management if applicable. It's a fast screening tool for whether a deal is even worth a closer look, not a substitute for actually itemizing real expected costs for a specific property.

Cash flow expectations should match your strategy

An investor prioritizing long-term appreciation in a high-growth market may accept thin or even slightly negative near-term cash flow, betting on equity growth and future rent increases. An investor building current income, or one who wants each property to stand on its own without needing outside cash to cover shortfalls, should set a firmer minimum cash flow threshold before buying. Neither approach is universally right — know which one you're actually running before you commit to a deal.