What it is good for
GRM needs two numbers you almost always have — asking price and rent — which makes it the fastest way to rank a long list before spending real time on any of it. Pull fifty listings in a metro, compute GRM on each, and the outliers announce themselves: a property at 7 in a market where everything else sits at 11 either has a problem or is a genuine opportunity, and either way it is worth the next hour. Used that way it is a triage tool, and triage tools are allowed to be crude.
Computing and comparing it
Annualize the rent, divide the price by it, and hold everything else constant. The comparison only means something inside one market and one property type, because the expense load that GRM ignores is exactly what differs between markets. Ten is a useful mental anchor in much of the cash-flow Midwest and South; the same ten in a high-tax coastal county describes a very different outcome. Use in-place rent when a property is tenanted and a defensible rent comp when it is vacant, since asking rent is the number sellers inflate first.
GRM = purchase price ÷ gross annual rent. $180,000 ÷ $18,000 = 10. Some investors quote a monthly version — price ÷ monthly rent — which is the annual figure multiplied by 12, so the same property reads 120.
What it hides
Everything between gross rent and actual profit. Two houses at GRM 10 can behave completely differently once you account for a property tax bill that is triple in one state, an insurance premium that doubled on the coast, a building with owner-paid utilities versus separately metered units, or a roof with two years left. GRM also says nothing about financing, which is where leverage makes or breaks the real return, and nothing about condition, which is where the first year of ownership is usually decided.
GRM versus cap rate and the 1% rule
The three are cousins. The 1% rule is roughly a GRM of about 8.3, since one percent of price per month is twelve percent per year. Cap rate is the grown-up version, using net operating income rather than gross rent, which is why it survives comparison across markets with different tax and insurance regimes while GRM does not. Screen on GRM, then underwrite the survivors on cap rate, cash-on-cash, and coverage before making an offer. The mistake is letting the screen become the decision: a low multiplier earns a property a closer look, never an offer, and the properties that clear the screen fastest are frequently the ones carrying a problem the price already knows about.
Put it to work
Gross rent multiplier calculator →
Related terms
- Cap rate — Capitalization rate — net operating income divided by purchase price, shown as a percent.
- 1% rule — A screening shortcut: monthly rent should equal at least 1% of the purchase price plus rehab.
- Price-to-rent ratio — Median home price divided by median annual rent for an area — a market-level gauge of whether buying is expensive relative to renting.
- NOI (net operating income) — Annual rental income minus all operating expenses, but before mortgage payments and income taxes.
- Operating expense ratio — Operating expenses divided by gross operating income, shown as a percent.