Rental Property Cash Flow Calculator

Always budget for vacancy even if your property is currently occupied. Markets shift, tenants move, and turnover costs add up. Most investors use 5-8% for single-family homes in stable markets, but you should research your specific submarket. High-turnover areas like college towns may warrant 10% or more, while properties with long-term tenants on multi-year leases can sometimes justify a lower figure.

Operating expenses are frequently underestimated by new investors. A common rule of thumb is the 50% rule, which suggests that roughly half of your gross rental income will go toward expenses excluding the mortgage. While this is just a guideline, it is a useful sanity check. Make sure your expense estimate includes property taxes, insurance, maintenance reserves (typically 5-10% of rent), landscaping, and any HOA fees.

Property management is optional if you self-manage, but you should still include it in your analysis. If you ever decide to step back from active management or buy properties in distant markets, you will need a manager. Including this cost from the start ensures your deal works even when you are not doing the day-to-day work yourself.

Cash flow is only one piece of the investment puzzle. A property with modest monthly cash flow might still be an excellent investment when you factor in principal paydown, tax benefits from depreciation, and long-term appreciation. Use this calculator alongside cap rate and cash-on-cash return tools to get the full picture of your investment's performance.

Run multiple scenarios by adjusting rent, vacancy, and interest rate inputs. Stress-testing your deal with higher vacancy rates or lower rents helps you understand the downside risk. If cash flow turns negative with just a small rent decrease or a modest vacancy increase, the deal may be too thin to pursue safely.