Cap rate and gross rent multiplier (GRM) both put a single number on a commercial property, and both get used to compare deals. But they answer different questions — and treating them as interchangeable is one of the fastest ways to misjudge a property.
The short version: GRM is a 10-second screen; cap rate is the real analysis. Here is why, and when each earns its keep.
What each one measures
Gross rent multiplier (GRM) = price ÷ gross annual rent. It uses gross rent and completely ignores vacancy and operating expenses. A property priced at $2,300,000 collecting $210,000 in gross rent has a GRM of about 11.
Cap rate (capitalization rate) = net operating income (NOI) ÷ price. It uses income after operating expenses, so it reflects the property’s true unlevered yield. That same property, if it nets $150,000 after expenses, carries a 6.5% cap rate.
Side by side
| GRM | Cap rate | |
|---|---|---|
| Formula | Price ÷ gross rent | NOI ÷ price |
| Accounts for expenses? | No | Yes |
| Best for | Fast first screen | Real valuation & comparison |
| Direction that’s “better” for a buyer | Lower | Higher (more yield) |
| Weakness | Ignores vacancy & OpEx | Needs an accurate NOI |
When to use each
Use GRM when you’re triaging a list of properties and only have asking price and gross rent — it ranks candidates in seconds. Use cap rate the moment a property makes the shortlist, because it accounts for the expenses that actually determine what you take home. Two buildings with an identical GRM can have very different cap rates once you subtract taxes, insurance, management, and maintenance.
Worked example
Two retail strips are each priced at $2,300,000 with $210,000 in gross rent — identical GRM of 11. Building A is triple-net with tenants covering most expenses, so its NOI is $175,000 (7.6% cap). Building B carries $70,000 more in owner-paid expenses, so its NOI is $105,000 (4.6% cap). Same GRM, wildly different deals. GRM flagged them as equal; cap rate told the truth.
The takeaway
Screen with GRM, decide with cap rate — and confirm the NOI and the cap against real comparable sales before you offer. That’s where deals are actually won or lost. Run both with the GRM calculator and the cap rate calculator, then pull a free broker opinion of value to check your assumptions against South Florida sales.
Free, no signup — and if you want the assumptions pressure-tested against real South Florida comps, ask for a broker opinion of value.
Cap Rate Calculator →GRM Calculator →Free Broker Opinion of Value →Frequently asked questions
Is GRM or cap rate better?
Cap rate is the better decision metric because it accounts for operating expenses; GRM is only a quick screen that uses gross rent. Use GRM to rank a list fast, then use cap rate to actually evaluate the finalists.
Can you convert GRM to a cap rate?
Not directly — GRM uses gross rent and cap rate uses net operating income, so you’d need the property’s expense ratio to bridge them. If a property’s expenses run about 35% of gross rent, an 11 GRM roughly corresponds to a ~6% cap, but that only holds at that specific expense ratio.
What is a good GRM and cap rate for commercial property?
Both depend on asset type, location, and risk, and there’s no universal target. Lower GRM and higher cap rate are generally better for a buyer, but always judge them against recent comparable sales for that specific asset and submarket rather than a fixed rule of thumb.