Cap rate — short for capitalization rate — measures the annual return a property would generate if you bought it in cash, expressed as a percentage of its current value. It's one of the fastest ways to compare income-producing properties against each other, but it's also one of the most misused numbers in real estate because it looks precise while leaving out most of what actually determines whether a deal is good.
What Cap Rate Tells You
At its core: Cap Rate = Net Operating Income ÷ Current Market Value. A property with a 7% cap rate is, in theory, generating a 7% annual return on its value before financing and appreciation are considered. That makes it useful for one specific job — ranking similar income-producing properties in a similar market against each other quickly, without needing to know how any particular buyer plans to finance the deal. (For the calculation itself, see our cap rate formula guide; for worked scenarios, see cap rate examples.)
What Cap Rate Doesn't Tell You
Cap rate is calculated as if you paid all cash, so it says nothing about how leverage will affect your actual cash-on-cash return. It also ignores appreciation potential, tax benefits, the timing and cost of capital expenditures, and — critically — the quality and condition of the property itself. Two properties with identical cap rates can carry very different risk: one might have a newer roof and stable long-term tenants, the other might be one major repair away from a very different NOI.
When Cap Rate Matters Most
Cap rate is most useful when you're evaluating buy-and-hold rental properties and want a quick, financing-neutral way to compare options in the same market — a duplex against a fourplex, or one neighborhood against another. Appraisers and brokers also use market cap rates (derived from recent comparable sales) to help estimate a property's value from its income, which is one reason cap rate shows up so often in listing marketing for investment properties.
Why It's Less Useful for Fix-and-Flip Deals
If your plan is to buy, renovate, and resell rather than hold for rental income, cap rate isn't the metric that should drive your offer. Flip profitability depends on after-repair value (ARV), renovation cost, and holding costs — not on the annual income a rental would produce, since you're not planning to rent it out. Investors sometimes calculate a hypothetical cap rate on a flip property anyway, but it's a secondary data point at best, useful mainly if you're deciding whether to pivot the property to a rental instead of selling.
What Counts as a "Good" Cap Rate
There's no universal good number — cap rates vary by market, property type, and how much risk investors in that market are willing to accept. Stable, in-demand markets with strong tenant pools tend to trade at lower cap rates because buyers accept a smaller return in exchange for lower risk; markets or property conditions with more uncertainty tend to trade at higher cap rates to compensate buyers for taking on that risk. Rather than chasing a specific target number you've seen quoted online, compare the cap rate of a property you're considering against recent comparable sales in that same submarket.
Limitations to Keep in Mind
- It assumes an all-cash purchase, which most investors don't actually make.
- It's only as accurate as the NOI behind it — inflated pro forma rent or an underestimated expense line will produce a misleadingly attractive cap rate.
- It says nothing about the timing of major capital expenses like a roof or HVAC replacement that could be due soon.
- It doesn't account for appreciation, which in many markets is a bigger driver of long-term return than annual income alone.
Used correctly, cap rate is a screening tool, not a decision by itself. Pair it with a realistic underwriting of the property's condition, the market's rent growth trajectory, and your own financing terms before you commit.