A rental property cap rate compares the income a property produces with its price or value. It can help investors compare properties, but it does not tell you how much cash you will keep after a mortgage payment or whether a property is a good investment on its own.
This guide explains the cap-rate formula, shows how to estimate net operating income (NOI), and walks through an example. It also covers the limits of the calculation so you can use it alongside other numbers when evaluating a rental.
What is a rental property cap rate?
Cap rate is short for capitalization rate. It expresses a property’s annual net operating income as a percentage of its purchase price or current value. Because the calculation excludes an individual buyer’s financing, it offers one way to compare the operating performance of different properties.
For example, two rentals may collect the same monthly rent but have different property taxes, insurance costs, maintenance needs, or purchase prices. Their cap rates may therefore differ substantially.
How do you calculate a rental property’s cap rate?
Cap rate (%) = (annual net operating income ÷ property price or value) × 100
For a potential purchase, investors commonly use the purchase price. When evaluating a property they already own, they may use a current estimate of its value. Use a consistent basis when comparing properties.
Step 1: Estimate effective annual income
Start with the rent the property could collect over a full year. Then account for a realistic amount of vacancy and uncollected rent. Add any other recurring property income that is reasonably supported. The result is an estimate of effective gross income.
Step 2: Subtract operating expenses
Operating expenses may include property taxes, insurance, routine repairs, maintenance, owner-paid utilities, landscaping, HOA dues, and property management fees. Use the costs expected for the particular property rather than a generic percentage.
Annual NOI = effective annual income − annual operating expenses. Fannie Mae similarly defines NOI as effective gross income minus operating expenses. See its NOI definition.
Mortgage principal and interest are not operating expenses in this calculation. Income taxes, depreciation, and major capital improvements also need separate analysis. If you have already reduced income for expected vacancy, do not subtract that same vacancy a second time as an expense.
Step 3: Divide NOI by price or value
Divide annual NOI by the property’s price or value, then multiply by 100 to express the result as a percentage.
Rental property cap-rate example
Suppose an investor is reviewing a rental with these estimated annual figures:
- Potential rent if occupied all year: $30,000
- Allowance for vacancy and uncollected rent: $2,000
- Effective annual income: $28,000
- Operating expenses: $8,000
- Annual NOI: $20,000
- Purchase price: $400,000
Cap rate = ($20,000 ÷ $400,000) × 100 = 5%.
The 5% figure describes estimated operating income relative to the purchase price. It is not a promise of a 5% profit or cash return. A repair that requires a major replacement, a longer vacancy, or different actual expenses could change the investment’s results.
What is a good cap rate for a rental property?
There is no cap rate that is automatically good for every rental. A useful comparison depends on the property’s location, type, condition, lease terms, income stability, expenses, and the risk an investor is willing to accept.
A higher cap rate can indicate more income relative to price, but it may also reflect an older building, deferred maintenance, uncertain rent, or greater vacancy risk. A lower cap rate can still make sense to an investor who values a different combination of property condition, location, and risk. Verify the income and expenses behind either number before drawing a conclusion.
Compare properties with similar characteristics and calculate each cap rate using the same approach to income, vacancy, expenses, and value. A broad percentage range cannot replace property-specific figures.
How cap rate differs from cash flow and cash-on-cash return
- Cap rate compares annual NOI with the property’s price or value. It does not include the buyer’s mortgage payments.
- Cash flow considers money remaining after operating expenses and financing payments, as well as other costs included in the investor’s analysis.
- Cash-on-cash return compares an investor’s annual cash return with the cash they invested. Financing and upfront cash requirements therefore matter.
A rental can have a reasonable cap rate and still produce little or negative cash flow after debt payments. Conversely, financing terms do not change the property’s cap rate when its NOI and value remain the same.
Common cap-rate mistakes
- Using gross rent instead of NOI: Subtract realistic operating expenses before calculating the rate.
- Assuming full occupancy: Account for vacancy and collection risk when estimating annual income.
- Using incomplete expense figures: Check taxes, insurance, maintenance, owner-paid services, and management costs.
- Mixing purchase price and current value: State which figure you used and compare properties consistently.
- Confusing cap rate with a total return: Review financing, major future repairs, cash flow, and possible changes in value separately.
How to use cap rates when comparing rentals
Calculate the cap rate for each property using supported rent estimates and a consistent expense method. Then investigate why the rates differ. A property’s lower price may explain a higher cap rate, but so might understated repairs or an optimistic rent estimate.
Before making a decision, review comparable rentals, property condition, expected capital work, financing terms, and cash flow under less favorable scenarios. Cap rate is a starting measure for comparison, not a complete investment decision.
Frequently asked questions
Does cap rate include mortgage payments?
No. The standard cap-rate calculation uses NOI before debt service. Calculate mortgage payments and cash flow separately to understand how financing affects your results.
Is a higher cap rate always better?
No. It may indicate more operating income relative to price, but it can also reflect greater risk or assumptions that need checking. Compare similar properties and verify the underlying figures.
Should I use asking rent or collected rent?
For an existing rental, begin with actual records and investigate any gap between advertised and collected rent. For a vacant or prospective rental, use supported market-rent estimates and allow for realistic vacancy. Label projections clearly.
Can a cap rate predict future returns?
No. It describes income relative to price or value using a particular set of figures. Future rent, expenses, vacancies, repairs, and property value may differ from the estimate.
