Most investors who lose money on rental properties made the same mistake: they fell in love with a property before running the numbers. These three metrics — cap rate, cash-on-cash return, and gross rent multiplier — let you evaluate any property in under 10 minutes.

Step 1: The 1% Rule Screen (30 Seconds)

Before doing any deeper analysis, apply the 1% rule: monthly rent ÷ purchase price ≥ 1%.

Purchase Price Minimum Monthly Rent to Pass 1% Rule
$100,000 $1,000
$150,000 $1,500
$200,000 $2,000
$300,000 $3,000
$400,000 $4,000

If a property fails this screen in your market, move on — or understand you’re buying for appreciation, not cash flow. In high-cost markets, you will rarely find a property meeting the 1% rule; in those markets, adjust your expectations toward appreciation and equity building.

Step 2: Calculate Net Operating Income (NOI)

NOI is the foundation of every other metric. It is gross rental income minus all operating expenses — but not including mortgage payments.

NOI Formula

NOI = Gross Rent − Vacancy − Operating Expenses

Worked Example: 3-Bedroom House, Purchase Price $230,000

Income/Expense Annual Monthly
Gross rent (market rate) $24,000 $2,000
Vacancy allowance (5%) −$1,200 −$100
Effective Gross Income $22,800 $1,900
Property taxes −$3,200 −$267
Homeowners insurance −$1,400 −$117
Maintenance/repairs (10% of rent) −$2,400 −$200
Property management (8% of rent) −$1,920 −$160
CapEx reserve (roof, HVAC, appliances) −$1,800 −$150
Total Operating Expenses −$10,720 −$894
Net Operating Income (NOI) $12,080 $1,006

Note: No mortgage payment is included in NOI. That’s intentional.

Step 3: Cap Rate

Cap Rate = NOI ÷ Purchase Price × 100

Using the example above: $12,080 ÷ $230,000 × 100 = 5.25% cap rate

Cap Rate Benchmarks by Market Type

Market Type Typical Cap Rate Range Example Markets
High-cost coastal 3–5% NYC, LA, San Francisco, Seattle
Major metros (mid-cost) 5–7% Denver, Austin, Nashville, Phoenix
Secondary cities 6–9% Columbus, Indianapolis, Memphis
Small cities / rural 8–12%+ Smaller Midwest/South markets

A 5.25% cap rate is decent for a mid-cost market. It means if you paid all cash, you’d earn 5.25% annually before taxes — comparable to a bond.

Cap rate does not account for financing. That’s why you also need cash-on-cash return.

Step 4: Cash-on-Cash Return

Cash-on-cash (CoC) measures actual cash flow relative to cash invested. This is the number that tells you whether the investment works for you with your actual mortgage.

Cash-on-Cash = Annual Pre-Tax Cash Flow ÷ Cash Invested × 100

Continuing the Example (25% Down, 6.9% Mortgage Rate)

Annual Monthly
NOI $12,080 $1,007
Mortgage payment (6.9%, 30-yr, $172,500 loan) −$9,780 −$815
Annual Pre-Tax Cash Flow $2,300 $192
Cash Invested Amount
Down payment (25%) $57,500
Closing costs (~2.5%) $5,750
Initial repairs / turnover $3,000
Total Cash Invested $66,250

Cash-on-Cash Return = $2,300 ÷ $66,250 = 3.47%

A 3.47% cash-on-cash return is modest. You’re earning $192/month in cash flow on a $66,250 investment. Many investors set a minimum threshold of 5–8% CoC before buying.

How Financing Affects Cash-on-Cash

Scenario Monthly Cash Flow Annual CoC
All cash, no mortgage $1,007 5.25% (= cap rate)
20% down, 6.9% rate $113 1.74%
25% down, 6.9% rate $192 3.47%
25% down, 5.5% rate $360 6.52%

Higher interest rates crush cash-on-cash returns. This is why many properties that penciled out at 3% rates no longer work at 6.9% — the math changed, not the property.

Step 5: Gross Rent Multiplier (GRM)

GRM is a faster, rougher metric. It’s the purchase price divided by annual gross rent.

GRM = Purchase Price ÷ Annual Gross Rent

Lower GRM = better value relative to gross income

$230,000 ÷ $24,000 = GRM of 9.6

GRM Range General Implication
Under 7 Potentially strong cash flow market
7–10 Moderate cash flow potential
10–15 Likely appreciation-focused market
Over 15 Very difficult to generate cash flow

GRM is useful for quick comparisons between multiple properties in the same market. It ignores expenses, so it’s not a substitute for full NOI analysis.

The Full Deal Analysis Template

Before making an offer, complete this analysis:

Metric Your Property Minimum Target
Monthly rent $_____ $_____
1% Rule (rent ÷ price) ____% ≥ 1.0%
NOI $_____ Positive
Cap Rate ____% ≥ 5% (market dependent)
Cash Invested $_____
Annual Cash Flow $_____ Positive
Cash-on-Cash Return ____% ≥ 5%
GRM _____ < 12
Vacancy Rate (local market) ____% < 8%
5-Year NPV at exit $_____ Positive

What the Numbers Don’t Tell You

Even strong numbers can hide problems:

  • Deferred maintenance: A fresh coat of paint hides an aging roof. Always get an inspection.
  • Rent at market rate?: Verify against comparable rentals — sellers sometimes show pro-forma (optimistic) rent figures, not actual achievable rent.
  • Neighborhood trajectory: A 9% cap rate in a declining market is worse than a 6% cap rate in an improving one.
  • Management reality: Self-managing saves 8–10% but costs you time. Model both scenarios.
  • Financing availability: Investment property loans require 15–25% down and carry higher rates than primary residence mortgages.

WealthVieu
Written by WealthVieu

WealthVieu researches and writes data-driven personal finance guides using primary sources including the IRS, Bureau of Labor Statistics, Federal Reserve, and Census Bureau.

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