Gross Rent Multiplier Calculator

Gross rent multiplier (GRM) is the simplest valuation ratio in residential and small commercial real estate: GRM = Purchase Price ÷ Annual Gross Rent. A duplex listed at $450,000 that collects $3,600 a month grosses $43,200 a year, so its GRM is 450,000 ÷ 43,200 = 10.4. Read it as the number of years of gross rent it would take to repay the purchase price if there were no expenses, no vacancy, and no financing.

The ratio rearranges two ways, which is why this calculator has three modes. If you know the GRM investors are paying in your submarket, you can solve for price: Price = Annual Gross Rent × GRM. If you know what you are willing to pay and the GRM you need to hit, you can solve for the rent the deal must produce: Annual Gross Rent = Price ÷ GRM. Brokers use the first form to price listings; investors use the second to set rent targets on value-add deals.

Some markets and some listing services quote a monthly GRM instead — price divided by monthly rent rather than annual rent. A monthly GRM is simply the annual GRM multiplied by twelve, so a 10.4 annual GRM is a 125 monthly GRM. This calculator shows both so you can compare listings no matter which convention the broker used. Mixing the two is the single most common GRM error, and it is off by a factor of twelve, which makes a bad deal look extraordinary.

GRM deliberately ignores operating expenses. That is a feature when you are screening thirty listings on a Saturday morning and a bug when you are deciding what to actually offer. Because it stops at gross income, GRM can be computed from a listing sheet in five seconds, before you have a rent roll, tax bill, or insurance quote. It is a filter, not an underwriting conclusion.

Duplex A is listed at $450,000 with two units renting at $1,800 each, so $43,200 a year and a GRM of 10.4. Duplex B is listed at $520,000 with the same $3,600 in combined monthly rent, giving a GRM of 12.0. Duplex C is listed at $385,000 with $3,300 a month, a GRM of 9.7. On gross rent alone, C is the cheapest income and B is the most expensive.

Now layer in the operating reality. Suppose Duplex A carries 38% operating expenses and a 5% vacancy allowance. Effective gross income is 43,200 × 0.95 = $41,040, and NOI is 41,040 × 0.62 = $25,445. Divide by the $450,000 price and the implied cap rate is 5.65%. That is the number a lender, an appraiser, or a serious buyer will actually use.

The ranking can flip once expenses differ. If Duplex C sits in a municipality with a much higher millage rate and carries 48% expenses instead of 38%, its NOI on $39,600 of gross rent at 5% vacancy is 37,620 × 0.52 = $19,562, which on a $385,000 price is a 5.08% cap rate. The property with the better GRM is the worse investment. That is precisely why GRM is a screen and cap rate is the decision.

Use the modes together. Screen with GRM to build a shortlist of five properties out of forty, then run the expense and vacancy inputs on this page to see the implied cap on each. Anything where the implied cap collapses relative to its GRM has an expense problem worth investigating before you tour it.

There is no universal good GRM, because the ratio embeds local property taxes, insurance costs, rent levels, and growth expectations. What follows are the ranges investors typically see in the United States as of the mid-2020s; verify against actual closed comps in your county before relying on them.

Small multifamily in low-cost Midwest and Southeast markets (Cleveland, Memphis, Birmingham, inland Georgia): GRM of 6 to 9 is common. Rents are high relative to price, but expense ratios and turnover are also high.

Sunbelt secondary markets (Tampa, Charlotte, San Antonio, Phoenix): GRM of 10 to 14. Insurance costs in Florida and coastal Texas have pushed effective expense ratios up sharply since 2022, so a 12 GRM there does not mean what a 12 GRM meant in 2019.

High-cost coastal metros (Los Angeles, Seattle, Boston, the New York outer boroughs): GRM of 15 to 22 and occasionally higher. Buyers accept low current income because they are underwriting appreciation, rent growth, and land value rather than yield.

Single-family rentals generally trade at higher GRMs than small multifamily in the same market because the buyer pool includes owner-occupants who are not buying on income at all. Class-C apartment buildings trade at the lowest GRMs because their expense ratios, turnover, and capital needs are the highest.

Short-term-rental properties should not be screened on GRM at all. Gross booking revenue carries management, cleaning, supply, and platform fees that can consume 35% to 50% of gross before any traditional operating expense, so the ratio is not comparable to long-term rentals.

GRM and cap rate are mathematically related whenever the expense ratio is constant. If NOI is a fixed fraction of gross rent, then Cap Rate is approximately (1 minus the expense ratio) divided by GRM. At a 40% expense ratio, a 10 GRM implies a 6.0% cap rate, and a 12.5 GRM implies a 4.8% cap. The reason the two metrics disagree in practice is that expense ratios are not constant across properties, which is exactly the information GRM discards.

The 1% rule is a rough cousin of GRM. It says monthly rent should be at least 1% of purchase price, which is the same as saying the annual GRM should be 8.33 or lower. This calculator shows the rent-to-price percentage alongside GRM so you can check both at once. In most coastal metros the 1% rule has been unattainable for a decade, which tells you the rule is a heuristic from a specific era and market, not a law.

Cash-on-cash return goes a step further than cap rate by adding financing. Two buyers can pay the same price for the same GRM and earn wildly different cash-on-cash returns depending on down payment, rate, and amortization. GRM is unlevered and financing-blind by construction, which makes it useful for comparing assets and useless for comparing deals structured differently.

A practical sequence: use GRM to shortlist, cap rate to value, DSCR to see what a lender will fund, and cash-on-cash to decide whether the equity is better deployed here than somewhere else. Skipping straight from GRM to an offer is how investors end up owning a property whose taxes reassess at the sale price the day after closing.

Using asking rent instead of collected rent. Vacancy, concessions, and delinquency mean the rent roll and the bank statements rarely match. Ask for twelve months of deposits, not a schedule of what units should rent for.

Using pro-forma rent as if it were in place. Sellers routinely list a property at a GRM computed on post-renovation market rents while the units are occupied by long-term tenants paying 25% under market. Compute two GRMs, one on in-place rent and one on pro-forma, and negotiate against the first.

Forgetting other income. Laundry, parking, storage, pet rent, and utility reimbursements can add 3% to 8% of gross in small multifamily. Excluding them overstates GRM and makes the deal look more expensive than it is.

Ignoring property tax reassessment. In states that reassess to market on transfer, the taxes in the seller's operating statement may be a fraction of what you will pay. GRM will not show you this because it never touches expenses.

Comparing across markets. A 9 GRM in a state with 2.3% effective property tax rates and a 9 GRM in a state with 0.6% rates are entirely different investments. Only compare GRMs within a submarket and property class.

Treating a low GRM as a bargain. Unusually low GRMs usually signal something: deferred maintenance, a declining submarket, a problem tenant base, or expenses that a new owner cannot control. Cheap income is often cheap for a reason worth discovering before closing.