A cap rate compares first-year NOI with the purchase price
Dividing NOI by price creates a common percentage for comparing an apartment, shopping center, warehouse, or hotel before debt. Reversing the formula estimates property value from NOI and a selected market cap rate.
Sensitivity is where the cap rate helps most. Small changes in NOI or the selected percentage can produce large changes in value, revealing which inputs deserve more research.
Changing NOI changes the cap rate
A cap rate is only as reliable as the income used in the numerator. Seller NOI may exclude management, understate repairs, use old property tax, or include income that will not continue. Two people can quote different cap rates for the same price because they normalized income differently.
Before cap rates are compared, NOI needs the same expense standards across every property. An incomplete expense list can make one building appear to offer a higher return even when its operations aren’t better.
A cap rate doesn’t show future rent or expenses
A low cap rate may reflect strong expected rent growth, limited risk, or an aggressive purchase price. A high cap rate may reflect attractive income, weak demand, short leases, major repairs, or tenant risk. The percentage provides no way to identify the correct explanation on its own.
For example, a 5 percent cap apartment and a 7 percent cap retail property cannot be ranked until their cash flows are understood. Retail income may disappear when a large tenant leaves, while apartment income may be constrained by regulation and rising operating costs. The two yields compensate an owner for different risks.
NOI ÷ valuecap-rate formula
0debt reflected
1 yearincome snapshot
A cap rate doesn’t include the mortgage
Cap rate is an unleveraged measure and says nothing about mortgage rate, amortization, maturity, or loan covenants. A 6 percent cap property financed with 8 percent debt can create weak or negative cash flow after principal payments.
Cap-rate analysis should be paired with debt-service coverage and a leveraged cash-flow model. The property and its financing are separate decisions, but they directly affect each other.
Use cap rates to compare similar properties and test price
Cap rates can screen, compare, and stress-test properties with stable income. A multi-year discounted cash flow is more appropriate when lease expiration or renovation causes income to change from year to year.
A quoted rate should be traced back to the property’s risk, growth, and capital requirements. Rebuilding the seller’s NOI with consistent expense standards shows whether the apparent yield reflects a better opportunity or a more optimistic expense estimate.
A cap rate is most useful when two similar properties use the same definition of NOI. Once the seller’s expenses have been rebuilt, the percentage can show whether one price is unusually high or low. I wouldn’t stop there. The mortgage, lease schedule, future rent, and major repairs belong in a separate cash-flow model because any one of them can matter more than a small difference in the first-year cap rate.
I used the filings, reports, public records, and articles linked below. Figures in the three case studies are practice numbers and are identified near the top of each article.
01JPMorgan cap rate guide↗02Federal Reserve Bank of San Francisco cap-rate research↗