Cap rate is not a return, and treating it as one costs money

Capitalization rate is net operating income divided by price. That is the whole definition, and almost every misuse of it comes from forgetting how little it contains.

It ignores debt. It ignores taxes. It ignores capital expenditure. It ignores what happens next year.

What it is genuinely useful for is comparing similar properties in the same market at the same moment. What it is not useful for is telling you what you will earn.

What goes into NOI, and what does not

Net operating income is gross rental income, less vacancy and credit loss, less operating expenses.

Operating expenses include property taxes, insurance, management, maintenance, utilities the owner pays, turnover costs, and reserves if you are honest about them.

Excluded, by convention: mortgage payments, depreciation, capital improvements, and income taxes.

That last set of exclusions is where the trouble starts. A roof is a capital item. It is also, unavoidably, money that leaves your account. A property with a twenty-two-year-old roof and one with a new roof can show identical NOI and represent very different propositions.

The three ways a quoted cap rate lies

It uses in-place rents that are not sustainable. A seller who signed a tenant at above-market rent last month, or who has been deferring the vacancy that is coming, shows a higher NOI than the property will produce.

It uses expenses that are not real. The most common omissions are management (because the seller self-managed), reserves for capital replacement (because they were never funded), and a realistic vacancy factor (because the property happened to be full on the day the numbers were pulled).

Strip a property of a management fee, a five percent vacancy allowance and a capital reserve, and you can move a quoted cap rate by well over a full point without touching anything real.

It is a pro forma. The word means projected. A pro forma cap rate describes a property that does not currently exist — one where the rents have been raised, the vacancies filled and the expenses reduced.

The seller is quoting you the outcome of work you have not done yet, at a price that assumes you have already done it.

Rebuilding the number yourself

Every underwriting exercise starts the same way: take the seller's numbers and rebuild them from the ground.

Use market rent, not in-place rent, unless leases are long and the tenants are credit-worthy.

Include a management fee whether or not you intend to hire a manager. Your time has a cost, and if you ever want to sell to someone who will hire one, the buyer will price it in.

Include vacancy at whatever the submarket actually runs, not at the number that makes the deal work.

Include a capital reserve. A common convention for residential is a few hundred dollars per unit per year, and for older buildings that is optimistic. The correct method is to inventory the major systems, estimate remaining life on each, and divide.

Use the property tax figure you will pay after the sale, not the one the seller pays. In many jurisdictions the assessment resets on transfer, and the difference has ruined otherwise reasonable deals.

Insurance likewise — quote it rather than assume it, particularly in coastal and wildfire-exposed markets where premiums have moved sharply.

What cap rate is actually telling you

It is a price signal about risk and growth expectations, the same as a bond yield.

A low cap rate means buyers are paying more per dollar of current income, either because they expect the income to grow or because they consider it safe. A high cap rate means the opposite — buyers demand more current income because they expect less growth or perceive more risk.

Which means a five cap in a supply-constrained coastal market and a nine cap in a declining small city are not a good deal and a bad deal. They are two different bets.

The nine cap is not free money. It is compensation for something, and your job is to find out what.

The numbers to use instead

Cash-on-cash return, which accounts for financing and tells you what the invested dollars produce.

Debt service coverage ratio, which tells you how much room there is before the loan is in trouble.

Internal rate of return over a realistic hold, which accounts for timing and the eventual sale.

Cash flow after capital reserves, in actual dollars, which is the number that determines whether you can sleep.

Cap rate belongs in the analysis as a sanity check on price. It does not belong at the center of it.

The one-line test

Before accepting any quoted cap rate, ask a single question: what expenses were excluded, and what would the number be with them in?

If the answer moves the cap rate by more than half a point, you were looking at marketing rather than analysis.

General information about real estate analysis, not investment, tax or legal advice. Property investment carries risk of loss. Consult qualified professionals about your own circumstances.