What Is a Real Estate Cap Rate, and Why In-Place Beats Pro-Forma

The capitalization rate is the most used and most misused number in commercial real estate. The formula takes ten seconds to learn. The judgment, which NOI goes in the numerator, is where deals are won, lost, and occasionally faked.

This piece covers the mechanics, what actually moves cap rates, and the distinction we consider the most important habit in underwriting: pricing a property on the income it produces today, in place, rather than the income a spreadsheet says it might produce later. Educational only; every property is its own case.

The formula and what it actually measures

A cap rate is net operating income divided by price:

Cap rate = NOI ÷ purchase price

A center producing $800,000 of NOI, bought for $10,000,000, was bought at an 8.0% cap. Run the formula backward and it becomes a pricing tool: $800,000 of NOI at a 7% cap implies roughly $11.4 million; at 9%, roughly $8.9 million.

Three properties of the number are worth internalizing:

It is an unlevered yield. The cap rate is the annual return the property itself throws off relative to its price, before any financing. For an all-cash buyer it approximates the actual first-year yield on the real estate. For a leveraged buyer it is the raw material that debt then amplifies or erodes.

It is a price expressed as a yield. "A 6% cap" and "16.7 times NOI" are the same statement. Low cap = expensive per dollar of income; high cap = cheap per dollar of income. Which brings us to the third property,

It prices risk and growth, not quality of the deal. Markets assign low cap rates to income they believe is safe and likely to grow, and high cap rates to income they believe is fragile. A high cap rate is not a bargain signal by itself; it is the market telling you what it thinks of that income stream. The opportunity is in disagreeing with the market correctly.

What moves cap rates

Cap rates move with both capital markets and property-level facts.

Interest rates and the spread. Cap rates tend to track long-term rates at a spread, historically a few hundred basis points over the 10-year Treasury for stabilized commercial assets, with the spread compensating for illiquidity, management burden, and risk. When Treasuries reprice, cap rates eventually follow, though sluggishly and unevenly.

Lease and tenant quality. Longer weighted-average lease term, stronger tenant credit, and NNN structures that pass expenses through all compress cap rates, because they make the NOI more predictable.

Asset type and location. Necessity-anchored retail in a secondary market trades wider than a coastal grocery-anchored center, which trades wider than industrial in a port market. Within a single metro, a quarter mile and one traffic signal can move pricing.

Liquidity and buyer depth. Assets in the $3-20 million range often trade at wider cap rates than the same quality of income at institutional scale, too large for most individual buyers, too small for institutions, which is precisely why disciplined buyers work that segment.

In-place versus pro-forma: the numerator problem

Every cap rate is only as honest as its NOI. And there are always at least two NOIs in circulation on any marketed deal.

In-place NOI is what the property earns right now: rents actually being paid under signed leases, minus actual operating expenses, with vacant space earning zero. It is auditable, trailing-12 financials, the current rent roll, real tax bills, real CAM reconciliations.

Pro-forma NOI is a projection: vacant suites leased at "market," below-market tenants renewed at higher rents, expenses "normalized" downward, a management fee conveniently omitted. Divide today's actual price by that future hypothetical income and you get the pro-forma cap rate, the number on the front page of most offering memoranda.

An illustration with round numbers. A center is offered at $10,000,000. The flyer says "8.5% cap." The fine print reveals the math: current NOI is $680,000 (a 6.8% in-place cap), and the 8.5% figure assumes the two vacant suites lease within a year at rents 15% above what sitting tenants pay, plus a 20% cut to the insurance line. The buyer is being asked to pay today for lease-up the seller never accomplished, and to hand the seller the value of the buyer's own future work.

The discipline is simple to state: the price should be justified by in-place NOI, and the pro-forma should be the buyer's upside, not the seller's comp. If a deal only works at pro-forma numbers, the buyer is not buying a property; they are buying a business plan at a price that assumes the plan already succeeded.

This is why buy-box criteria expressed as in-place cap rates, the approach described on our strategy page, are more restrictive than they sound. An "8% cap" screen means 8% on audited, current, actually-collected income. Marketed deals meeting that bar on in-place numbers are a small fraction of the deals whose flyers claim it.

Adjusting even the in-place number

In-place NOI still requires scrubbing before it deserves the denominator:

• Mark the expenses to your ownership, not the seller's. Owner-managed properties often show no management fee; insert a market one. Long-held properties often carry pre-reassessment tax bills; model taxes at your purchase price.
• Check collections against billings. A rent roll shows what tenants owe. The bank statements show what they pay.
• Look for expiring income. In-place NOI that includes a tenant whose lease expires in eight months is partly pro-forma wearing an in-place costume. Weight income by its remaining term.
• Reserve for capital. NOI conventionally excludes capital expenditures, which is how a 30-year-old roof hides inside an attractive yield. A cap rate is not a cash flow forecast.

Going-in versus exit: the same number, twice as dangerous

The cap rate appears twice in any hold-period model: at entry (going-in cap) and at exit, where a terminal cap rate is applied to final-year NOI to estimate sale proceeds. The exit assumption is quietly the most powerful lever in most underwriting. On a projected $900,000 of exit-year NOI, a 7.5% exit cap implies a $12.0 million sale; assume 6.5% instead and the model conjures an extra $1.8 million of value from a single cell.

Two conservative conventions guard against this. First, assume the exit cap at or slightly above the going-in cap, properties age, leases shorten, and pricing at exit is unknowable, so let the property's income growth carry the return rather than assumed market compression. Second, run the sensitivity: if the deal's outcome flips from acceptable to poor when the exit cap widens 100 basis points, the "value" in the model is a market bet, not a real-estate plan. Over a 3-5 year hold, entry price and income improvement are largely controllable; the exit environment is not.

What the cap rate cannot tell you

The cap rate is a snapshot: one year's income against one price. It says nothing about growth (a 6% cap with 3% annual escalations outruns a flat 7.5% cap within the decade), nothing about capital needs, nothing about financing, and nothing about how hard the income will be to keep. It is the beginning of underwriting, the screen that decides which deals earn a full model, never the conclusion. Used that way, on honest in-place numbers, it remains the most efficient filter in the business.