Gross Rent Multiplier (GRM): What It Is and How to Use It
The fastest way to compare two listings — and a number that will happily rank a money-losing property first.
9.5
Price ÷ gross annual rent on the $240,000 example. Blind to every expense.
The formula
GRM = Purchase price ÷ Gross annual scheduled rent
Some markets quote a monthly GRM instead — same idea, divided by monthly rent. Multiply by 12 to compare.
The $240,000 example
- Purchase price
- $240,000
- Gross scheduled rent ($2,100 × 12)
- $25,200
GRM = 9.5
Read as: you are paying 9.5 years of gross rent for the building. It is deliberately crude — no vacancy, no expenses, no financing. What it buys you is speed: you can compute it from a listing headline, on a phone, for forty properties in the time it takes to underwrite one.
What GRM ranges mean
| GRM | Equivalent monthly rent-to-price | Typically found in |
|---|---|---|
| Under 7 | Above 1.2% | Tertiary markets, older C-class stock, or a property with a problem. |
| 7 – 9 | 1.1% – 0.9% | Cash-flow markets — much of the midwest and south. |
| 9 – 12 | 0.9% – 0.7% | Balanced secondary metros. Most 2026 rental deals land here. |
| 12 – 16 | 0.7% – 0.5% | Strong-growth metros. Cash flow is thin to negative with debt. |
| Above 16 | Under 0.5% | Prime coastal. You are buying appreciation, full stop. |
GRM and the 1% rule are the same rule
Where GRM goes wrong
Consider two houses, both $240,000, both renting for $2,100. Identical GRM of 9.5. One is a 2015 build in a low-tax county with tenant-paid utilities; the other is a 1948 house in a high-tax jurisdiction with an owner-paid water bill and a 22-year-old roof.
| Newer, low-tax | Older, high-tax | |
|---|---|---|
| Gross scheduled rent | $25,200 | $25,200 |
| GRM | 9.5 | 9.5 |
| Operating expenses + vacancy | $8,100 (32%) | $13,600 (54%) |
| NOI | $17,100 | $11,600 |
| Cap rate | 7.13% | 4.83% |
That gap is not exotic. It is the ordinary spread between a low-expense and a high-expense property, and GRM is structurally blind to all of it. Which is why GRM belongs at the triage stage and nowhere near the decision.
Converting GRM to cap rate
If you know a market’s typical operating expense ratio, GRM converts directly into an estimated cap rate:
Cap rate ≈ (1 − vacancy) × (1 − OER) ÷ GRM
Vacancy as a decimal; OER as operating expenses divided by effective gross income.
Checking it on the $240,000 example
- Vacancy
- 5%
- OER ($8,936 ÷ $23,940)
- 37.3%
- GRM
- 9.5
- (1 − 0.05) × (1 − 0.373) ÷ 9.5
- 6.27%
- Actual cap rate ($15,004 ÷ $240,000)
- 6.25%
Within two basis points — the shortcut works.
This is genuinely useful for screening: once you know your market runs roughly 40% OER, any GRM converts to an approximate cap rate in your head. It is also a good reminder of what GRM is missing — the entire OER term, which is the difference between the two houses above.
How to actually use it
Compute GRM on every listing you look at, sort by it, and underwrite the bottom of the list properly. That is the whole workflow. When a property with an attractive GRM survives a real analysis — vacancy, management, reserves, financing — you have found something. When it does not, you have spent five minutes instead of an hour. Run the survivors through the free calculator to get the numbers that matter.
Frequently asked questions
What is a good gross rent multiplier?
Lower is cheaper, but the range that counts as good is entirely market-dependent: 7 to 9 is normal in cash-flow markets, 9 to 12 in balanced secondary metros, and above 14 in high-growth coastal markets. Compare a property's GRM to other listings in the same submarket rather than to a national benchmark.
GRM vs cap rate — which should I use?
GRM for screening a long list quickly, cap rate for deciding. GRM ignores operating expenses entirely, so it cannot distinguish a low-expense property from a high-expense one at the same price and rent — and that difference routinely moves the actual yield by two percentage points or more.
Should GRM use gross or effective rent?
The standard is gross scheduled rent, before vacancy. Some people compute an effective GRM using collected rent; both are defensible, but you must apply the same convention to every property you compare or the ranking is meaningless.
How do I convert GRM to cap rate?
Cap rate is approximately (1 minus vacancy) times (1 minus the operating expense ratio), divided by GRM. With 5% vacancy and a 37% expense ratio, a GRM of 9.5 works out to roughly a 6.3% cap rate.