Gross Rent Multiplier (GRM), Capitalization Rate (Cap Rate) and Internal Rate of Return (IRR) are three terms you’ll often encounter in commercial real estate. By the time you finish this short article, you should have a good idea about what they are, why and when you would use them, and what their limitations are.

The GRM is the easiest to calculate, as well as the least informative number you’ll hear when evaluating commercial real estate. If you know the asking or selling price of a property as well as the annual maximum income that can be generated from the current leases, you can calculate the GRM.

As an example, let’s take a multifamily property. Assume the asking price is $1 million. There are 20 one-bedroom units, each renting for $500 per month and 20 two-bedroom units each bringing in $650 a month. Assuming no vacancies, losses or concessions, that totals $11,300 per month, or $135,600 of potential rental income per year. Dividing the purchase price by the Gross Potential Rental Income gives you the GRM, in this case 7.37.

By itself, that number has virtually no meaning. It tells you nothing about vacancies, concessions, expenses or taxes. About the only way you could use this number is to compare it to other GRMs for similar properties in the same general area. Only if one stood out from the pack would you use this to eliminate a property from further consideration, or to follow up with additional inquiries. Most investors don’t even consider the GRM, but jump straight to the Cap Rate.

The Cap Rate uses the Net Operating Income, or NOI, as its starting place. Since the NOI reflects vacancies, losses and expenses, and also adds in other income as from an on-site laundry, it’s a much better reflection of the actual operation of the property.

The Cap Rate is used mainly when buying or selling a property. You can calculate the Cap Rate if you know the NOI and the selling or asking price. To find out what the cap rate was on a recent comparable sale, divide the NOI by the purchase price. So, if the NOI is projected to be $100,000 next year, and the sale price is $1,000,000, doing the division yields a Cap Rate of 10%. This is equivalent to putting $1,000,000 into a bank account at 10% interest and getting interest payments of $100,000 per year. Continue reading