Cap rate and cash-on-cash return are two common rental property metrics, but they measure different things. Cap rate evaluates the property itself before financing. Cash-on-cash return evaluates the cash produced by the investor's actual cash invested after financing.
What cap rate measures
Capitalization rate equals net operating income divided by the property's current value or purchase price. Net operating income excludes mortgage payments, income taxes and depreciation. This makes cap rate useful for comparing properties with different financing structures, but it does not tell you how much cash will remain after debt service.
What cash-on-cash return measures
Cash-on-cash return equals annual pre-tax cash flow divided by the total cash invested. The investment may include the down payment, closing costs, initial repairs and other acquisition costs. Because the denominator reflects the investor's cash, financing terms can change the result substantially.
Why the metrics can disagree
A property can have an attractive cap rate but weak cash-on-cash return if the mortgage is expensive or the down payment is large. The reverse can also happen when favorable financing creates strong cash flow relative to a small cash investment. Neither metric should be used alone.
Common calculation mistakes
- Using gross rent instead of net operating income for cap rate
- Ignoring vacancy, repairs or professional management
- Leaving closing costs out of the cash invested amount
- Comparing cap rates from different markets without considering risk
How to use both metrics
Use cap rate to compare the underlying property and cash-on-cash return to test the financing plan. Then stress-test vacancy, repairs, insurance and interest rates. These are analytical tools, not promises of performance, and local market data should be verified before making an offer.
Sources and further reading
- IRS Publication 527: Residential Rental Property
- IRS Topic No. 404: Rental Income and Expenses
- U.S. Department of Housing and Urban Development rental resources
Rules and tax treatment can change and may vary by state. Check the current official guidance for the property location before relying on this information.
