Rental investing explained

How to estimate rental property cash flow.

Cash flow is what remains after realistic rental income and recurring property costs are accounted for. It is a screening tool, not a promise of future performance.

01 · Income

Start with realistic rent

Use a current long-term rental estimate for a comparable property, then adjust for bedrooms, bathrooms, condition, parking, furnishings, and local demand. Annual gross rent is monthly rent multiplied by twelve.

Monthly rent × 12 = annual gross rent

02 · Costs

Subtract every recurring expense

Include the mortgage payment, property taxes, insurance, homeowners association dues, vacancy reserve, maintenance reserve, management, utilities, and any recurring service costs. A missing expense can make a weak deal look attractive.

Rent − operating costs − mortgage = monthly cash flow

Brief example

Suppose a property rents for $2,000 per month. If taxes, insurance, association dues, vacancy, and maintenance total $550 per month, and the mortgage payment is $1,050, estimated cash flow is $2,000 − $550 − $1,050 = $400 per month, or $4,800 per year before income taxes.

Positive cash flowIncome exceeds the costs included in the estimate.
Negative cash flowIncome does not cover the costs included in the estimate.
Use the calculator to test a property

PositiveCash.me combines property data, rent estimates, financing assumptions, and adjustable reserves. Replace estimates with current quotes before making an investment decision.

Analyze an address →