Investing

How to Analyze a Rental Property Investment

Most first-time real estate investors focus on the wrong number: purchase price. Experienced investors focus on income relative to cost. This guide walks you through the four metrics every rental property analyst uses, and when each one tells you something the others don't.

Step 1: Estimate Gross Rental Income

Start with what the property can earn before expenses. For long-term rentals, this is annual rent at market rate. For STRs, it's annual gross revenue based on average daily rate (ADR) times occupancy rate:

Gross Revenue (STR) = ADR × Occupancy Rate × 365

Example:
  ADR = $150/night
  Occupancy = 65%
  Gross Revenue = $150 × 0.65 × 365 = $35,587/year

For long-term rentals, use current market rents for comparable units — not the seller's claimed rent, which may be below-market on inherited tenants.

Step 2: Calculate Net Operating Income (NOI)

NOI is the single most important number in rental property analysis. It measures what the property earns after operating expenses but before debt service (mortgage payments):

NOI = Gross Income − Operating Expenses

Operating Expenses typically include:
  • Property taxes
  • Insurance
  • Property management (8–12% of gross rents)
  • Maintenance and repairs (budget 1–2% of property value/year)
  • HOA fees (if applicable)
  • Vacancy allowance (5–10% of gross rents)
  • Utilities paid by landlord
  • STR platform fees (3% Airbnb host fee, or ~15% for full-service)

What is NOT in NOI:
  • Mortgage principal and interest
  • Depreciation
  • Income taxes
  • Capital expenditures (CapEx is sometimes added separately)

Step 3: Capitalization Rate (Cap Rate)

Cap rate tells you the return you'd earn if you bought the property with all cash — it's a property-level metric that removes the effect of your financing:

Cap Rate = NOI ÷ Purchase Price

Example:
  NOI = $18,000/year
  Purchase Price = $300,000
  Cap Rate = $18,000 ÷ $300,000 = 6.0%

What's a good cap rate? It depends heavily on the market. A 5% cap rate in Manhattan or San Francisco is considered acceptable; a 5% cap rate in rural Mississippi suggests you're overpaying. General benchmarks:

Major gateway cities (NYC, LA, SF, Seattle): 3–5%
Mid-tier metros (Denver, Austin, Nashville, Phoenix): 5–7%
Secondary and tertiary markets: 7–10%+

Use cap rate to compare properties in the same market, not across markets. It's most useful for commercial and multifamily properties — less so for single-family where appreciation is a larger component of return.

Step 4: Cash-on-Cash Return

Cash-on-cash (CoC) measures what you actually earn relative to the cash you put in. Unlike cap rate, it accounts for your financing:

Cash-on-Cash Return = Annual Pre-Tax Cash Flow ÷ Total Cash Invested

Annual Pre-Tax Cash Flow = NOI − Annual Debt Service

Example:
  NOI: $18,000/year
  Annual mortgage payment (P+I): $14,400/year
  Pre-Tax Cash Flow: $3,600/year

  Down payment: $60,000
  Closing costs: $4,500
  Initial repairs: $8,000
  Total Cash Invested: $72,500

  Cash-on-Cash Return = $3,600 ÷ $72,500 = 4.97%

Investors generally target 8–12% CoC for long-term rentals and 15%+ for STRs, though market conditions in 2023–2025 have compressed these targets significantly in many high-cost markets.

Step 5: Gross Rent Multiplier (GRM)

GRM is a quick-and-dirty screening tool, not a final decision metric:

GRM = Purchase Price ÷ Annual Gross Rents

Example:
  Purchase Price: $300,000
  Annual Gross Rents: $24,000
  GRM = 300,000 ÷ 24,000 = 12.5

A lower GRM is better. Use it to quickly filter a list of properties before running full NOI/cap rate analysis. Typical benchmarks: GRM under 10 is interesting in most markets; over 15 deserves scrutiny.

STR vs. Long-Term Rental Analysis

For short-term rentals, add these considerations to the standard analysis:

STR platform fees: 3% host service fee (Airbnb) to 15–25% if using a full-service property manager.
Furnishing and setup costs: $5,000–$30,000 depending on property size and quality level. Amortize over expected useful life (3–7 years).
Higher maintenance: STRs have 3–5× higher maintenance costs than long-term rentals due to turnover, wear, and guest damage.
Occupancy risk: STR income is more volatile than long-term rents. Model at 55%, 65%, and 75% occupancy to understand your downside.
Regulatory risk: Cities can ban or restrict STRs with minimal notice. Always check whether the property is in a jurisdiction with active STR regulations.

The 1% Rule (and Why It's a Rough Heuristic)

The "1% rule" says a good rental property should rent for at least 1% of its purchase price per month (e.g., a $300,000 property should rent for at least $3,000/month). This heuristic worked well in the 2010s but largely fails in today's markets:

In major metros, 0.5–0.7% is more typical for single-family homes.
STRs can clear 1%+ in tourist markets — but come with the risks above.
Use it as a quick filter only, not a final decision.

This guide is for educational purposes. Rental income projections involve uncertainty; consult a licensed CPA and financial advisor before making investment decisions.