# Gross Rent Multiplier (GRM) — What It Is and How to Use It for STR Deals

> Gross Rent Multiplier (GRM) is a fast property screening ratio used to compare STR deals. Learn the formula, a worked example, and when to use GRM vs cap rate and cash-on-cash return.

Canonical: https://www.underwriteapp.com/learn/gross-rent-multiplier


## Definition

**Gross Rent Multiplier** (GRM) is the ratio of a property's purchase price to its annual gross rental income. It tells you how many years of gross rent equal the purchase price.

$$\text{GRM} = \frac{\text{Property Purchase Price}}{\text{Annual Gross Rental Income}}$$

A GRM of 8 means you are paying 8 years of gross rental income to acquire the property. A GRM of 12 means 12 years. **Lower is better** — it indicates you are getting more gross income relative to what you paid.

GRM is intentionally rough. It ignores expenses, vacancy beyond your estimate, and financing. That makes it extremely fast to compute from listing data alone, which is why investors use it as a first-pass filter before committing to deeper analysis.

## Formula and Worked Example

**Property:** 3-bedroom lakefront cabin, Lake Anna, VA  
**Purchase price:** $520,000  
**Estimated nightly rate (ADR):** $310  
**Estimated occupancy:** 62%

### Step 1 — Calculate annual gross rental income

Annual Income = ADR × Occupancy Rate × 365

$$\$310 \times 0.62 \times 365 = \$70,153$$

### Step 2 — Divide purchase price by annual income

$$\text{GRM} = \frac{\$520,000}{\$70,153} = \mathbf{7.4}$$

This property costs 7.4 years of gross rent income. For a lake market, that is a solid entry point worth investigating further.

### Reverse-engineering a target price

GRM also works in reverse. If you know comparable properties sell at a GRM of 8 and your income estimate is $70,000, your maximum offer price is:

$$\text{Target Price} = \text{GRM} \times \text{Annual Income} = 8 \times \$70,000 = \$560,000$$

This is useful when evaluating off-market deals or making initial offers before you have full financials.

## GRM vs. Cap Rate vs. Cash-on-Cash Return

All three metrics serve different purposes at different stages of due diligence.

| Metric | Formula | Includes Expenses? | Includes Financing? | Best Used For |
|--------|---------|-------------------|--------------------|--------------------|
| **Gross Rent Multiplier** | Price ÷ Annual Gross Income | No | No | Fast first-pass screening |
| **Gross Rental Yield** | Annual Gross Income ÷ Price | No | No | Comparing revenue-to-price across markets |
| **Cap Rate** | NOI ÷ Property Value | Yes (operating) | No | Property value comparison, independent of financing |
| **Cash-on-Cash Return** | Annual Cash Flow ÷ Cash Invested | Yes (all) | Yes | Your actual leveraged return |

GRM and [gross-rental-yield](/learn/gross-rental-yield) are two sides of the same coin — GRM is the inverse of GRY expressed as a multiplier rather than a percentage. A GRY of 13.5% equals a GRM of 7.4 (1 ÷ 0.135 ≈ 7.4).

The analysis path for most STR investors looks like this:

1. **GRM** — screen dozens of listings in minutes using ADR and occupancy estimates
2. **[Cap rate](/learn/what-is-cap-rate)** — evaluate shortlisted properties after building a full expense model
3. **[Cash-on-cash return](/learn/cash-on-cash-return)** — finalize the decision using your specific financing terms

Do not substitute GRM for cap rate or cash-on-cash return. It is an entry filter, not a final answer.

## STR-Specific Considerations

### Seasonal variation compresses gross income

Most GRM benchmarks originate from long-term rental analysis, where income is steady year-round. STRs are inherently seasonal. A Poconos ski cabin might generate 70% of its annual income in 14 weeks. When estimating annual income for GRM, use a full-year projection — not peak-season extrapolation — or you will overstate income and understate the multiplier.

**Example of the error:** If a property earns $8,000 in a peak month and you annualize at $96,000, your GRM looks like 5.4. The same property earning $55,000 across a realistic full year gives a GRM of 9.5 — a very different picture.

### Platform fees reduce effective gross income

Airbnb, Vrbo, and other platforms charge host fees of 3–15% of booking revenue depending on the service model. Some investors include platform fees as a deduction and call the remainder "gross income." Others use total booking revenue as gross.

Be consistent: **GRM is most comparable across properties when you use total booking revenue before platform fees.** If you are comparing one property listed exclusively on Airbnb at 3% host fee against another managed by a full-service company taking 25%, the fee structure affects net income, not gross income, and belongs in your cap rate or cash-on-cash analysis.

### New STR regulations affect income stability

Markets with active regulatory risk (city-level permit caps, HOA restrictions, zoning changes) carry income uncertainty that GRM cannot capture. A GRM of 7 in a market about to implement strict STR licensing may perform worse than a GRM of 10 in a stable, STR-friendly market. Factor regulatory environment into any GRM comparison.

## Benchmarks by Market Tier

| Market Tier | Example Markets | Typical GRM Range |
|-------------|-----------------|------------------|
| Tier 1 — High-cost coastal | Hawaii, Malibu, Miami Beach | 12–18 |
| Tier 2 — Popular leisure | Smoky Mountains, Blue Ridge, Poconos | 6–10 |
| Tier 3 — Secondary/emerging | Smaller lake towns, rural cabins | 4–8 |
| Urban short-term | Nashville, Austin, Denver (urban core) | 8–13 |

Lower GRM in Tier 2 and Tier 3 markets does not automatically mean better investments — it often reflects higher vacancy risk, seasonality, and lower liquidity at exit. Use the benchmarks as context, not targets.

## Limitations of GRM

**It ignores all operating expenses.** STR expenses typically consume 40–55% of gross revenue. Two properties with identical GRMs can have dramatically different cap rates if one has higher management fees, insurance, or property taxes. GRM cannot distinguish between them.

**It ignores vacancy beyond your estimate.** The occupancy figure you use to project annual income is a forecast, not a guarantee. Regulatory changes, new supply, or a weak booking season can compress income significantly without changing the purchase price.

**It ignores financing entirely.** A property with a GRM of 8 might generate strong cash-on-cash returns with a low-rate assumable mortgage but negative cash flow at current market rates. GRM tells you nothing about your actual return as a leveraged buyer.

**It is sensitive to income projection errors.** Because GRM uses gross income rather than NOI, any error in your ADR or occupancy estimate flows directly into the ratio. A 10% overestimate in income inflates GRM by the same amount, making a property look better than it is.

Use GRM to decide which properties deserve 10 more minutes of your time — not to decide which property to buy. Once a deal clears your GRM threshold, move to [cap rate](/learn/what-is-cap-rate) and [cash-on-cash return](/learn/cash-on-cash-return) before making any offer.

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