The gross rent multiplier — GRM — is one of the simplest valuation ratios in real estate. It compares a property’s price to the rent it collects, without touching expenses, vacancy or financing. That simplicity makes it fast, and it also makes it easy to over-trust.
The formula
A GRM of 9 means the property costs nine times its annual rent. Lower GRMs mean more rent per dollar of price; higher GRMs mean less.
GRM is the flip side of gross yield. Gross yield is annual rent ÷ price; GRM is price ÷ annual rent. A GRM of 10 is the same as a 10% gross yield, and a GRM of 8 is a 12.5% gross yield.
A worked example
A fourplex listed at $480,000
Each of the four units rents for $1,150 per month.
| Item | Amount |
|---|---|
| Monthly gross rent (4 × $1,150) | $4,600 |
| Annual gross rent | $55,200 |
| Price | $480,000 |
| GRM (price ÷ annual rent) | 8.70 |
| Equivalent gross yield | 11.5% |
Hypothetical numbers for illustration.
Using GRM to estimate value
GRM is most often used as a comparison tool. If similar properties in the same area recently sold at a known GRM, that multiple can be applied to a subject property’s rent to estimate a value:
| Comparable sale | Price | Annual rent | GRM |
|---|---|---|---|
| Comp 1 | $510,000 | $57,600 | 8.85 |
| Comp 2 | $455,000 | $52,800 | 8.62 |
| Comp 3 | $530,000 | $60,000 | 8.83 |
| Average | 8.77 |
Applying the average GRM of 8.77 to the example fourplex’s $55,200 annual rent gives an estimated value of about $484,011. The listing price of $480,000 sits below that figure by about $4,011.
This is a rough check, not an appraisal. It works best when the comparables are genuinely similar: same area, similar size and age, similar unit mix, and similar expense structure.
GRM vs. cap rate
GRM and cap rate both relate price and income, but at different levels:
| GRM | Cap rate | |
|---|---|---|
| Income used | Gross rent | Net operating income |
| Includes vacancy? | No | Yes |
| Includes expenses? | No | Yes |
| Calculation | Price ÷ rent | NOI ÷ price |
| Better when expense data is | Unavailable | Available |
The main reason to use GRM is that rent is easy to find and expenses often aren’t. A rent roll might be available early on, but a full operating statement may not be.
Where GRM can mislead
Because GRM ignores expenses, two properties with the same GRM can have very different net income.
Same GRM, different expenses
Imagine two fourplexes, both priced at $480,000 with $55,200 in annual rent — an identical GRM of 8.70.
| Building A | Building B | |
|---|---|---|
| Operating expenses (incl. vacancy) | $20,976 (38% of rent) | $30,360 (55% of rent) |
| NOI | $34,224 | $24,840 |
| Cap rate | 7.13% | 5.17% |
Hypothetical numbers for illustration.
Building B might have owner-paid heat, higher property taxes or older systems that need more maintenance. GRM can’t see any of that. The cap rates make the difference visible: 7.13% versus 5.17%.
Other things GRM doesn’t account for:
- Vacancy. A building with chronic vacancy and one that’s always full look the same if their scheduled rent matches.
- Below-market or above-market rents. GRM uses current rent; if leases are well below market, the property’s potential is understated — and if they’re above market, it may be overstated.
- Condition. A building that needs a new roof and one that just got one can have the same GRM.
- Financing. Like cap rate, GRM says nothing about the loan or cash flow.
When GRM is most useful
- Early screening, when only rent and price are known.
- Comparing similar properties in the same neighborhood, where expense structures tend to be alike.
- A quick check on a listing price against recent sales.
- Markets where GRM is a common shorthand, such as small multifamily in some areas, where brokers and buyers quote it routinely.
Once expense information is available, moving on to NOI, cap rate and cash flow gives a much fuller picture.
A note on monthly vs. annual GRM
Most sources calculate GRM with annual rent. Some, particularly for single-unit rentals, use monthly rent instead, which produces a number 12 times larger (a 9.0 annual GRM is a 108 monthly GRM). Neither is wrong, but mixing them in a comparison is. It’s worth confirming which version a quoted GRM uses.
Frequently asked questions
Is a lower GRM always better? A lower GRM means more gross rent per dollar of price, but it doesn’t account for expenses, condition or location. A low GRM can come with high operating costs or significant deferred maintenance, so it’s a starting point for comparison rather than a conclusion.
Should other income be included in GRM? Some analysts include recurring other income such as parking or laundry; others use rent only. Either is reasonable as long as every property in the comparison is calculated the same way.
How is GRM different from price per unit? Price per unit divides price by the number of units and ignores rent entirely. GRM ties price to income, so it reflects differences in rent levels between buildings that price per unit can’t.
The takeaway
Gross rent multiplier is price divided by annual gross rent — a quick way to compare how expensive properties are relative to their income, or to estimate value from comparable sales. Because it ignores vacancy, expenses and financing, it’s a screening and sanity-check tool. Properties with similar GRMs can have very different net income, which is why cap rate and cash flow follow it in a fuller analysis.