The 5 Key Metrics Every Rental Investor Must Know
Rental property analysis comes down to understanding five core metrics. Each tells you something different about the investment's performance and risk profile.
1. Net Operating Income (NOI)
Revenue minus operating expenses (before debt)
2. Cap Rate
NOI ÷ Property Value (return without financing)
3. Cash-on-Cash Return
Annual cash flow ÷ Cash invested
4. DSCR
NOI ÷ Annual debt service (loan coverage)
5. Cash Flow
NOI minus debt service = money in your pocket
Net Operating Income (NOI)
NOI is the foundation of rental property analysis. It represents the income a property generates after operating expenses but before debt service (mortgage payments).
NOI Formula
NOI = Gross Rental Income - Vacancy - Operating Expenses
Operating Expenses Include:
- Property taxes: Annual tax bill ÷ 12
- Insurance: Landlord/hazard policy
- Property management: Usually 8-10% of rent
- Maintenance & repairs: Budget 5-10% of rent
- Vacancy allowance: Usually 5-10% of gross rent
- Utilities: If landlord-paid
- HOA fees: If applicable
- Lawn care/snow removal: If landlord-responsible
NOI Example
Monthly Rent: $1,800
Annual Gross Rent: $21,600
Less Vacancy (5%): -$1,080
Less Property Taxes: -$2,400
Less Insurance: -$1,200
Less Management (8%): -$1,728
Less Maintenance (5%): -$1,080
NOI = $14,112/year ($1,176/month)
Use our NOI Calculator to quickly calculate net operating income for any property.
Cap Rate (Capitalization Rate)
Cap rate measures a property's return independent of financing. It answers: "If I paid all cash, what would my return be?" This makes it useful for comparing properties regardless of how they're financed.
Cap Rate Formula
Cap Rate = NOI ÷ Property Value × 100
Cap Rate Example
NOI: $14,112/year
Purchase Price: $200,000
Cap Rate = $14,112 ÷ $200,000 = 7.06%
What's a Good Cap Rate?
A+ Markets
3-5%
High appreciation
B Markets
5-7%
Balanced
C Markets
7-10%
Cash flow focus
D Markets
10%+
Higher risk
Cap Rate Reality Check
High cap rates often signal higher risk: rough neighborhoods, deferred maintenance, or problem tenants. Low cap rates in premium areas may offer better appreciation and tenant quality. Match cap rate to your investment strategy.
Use our Cap Rate Calculator to analyze any property.
Cash-on-Cash Return
Cash-on-cash return is the most practical metric for leveraged investors. It measures your actual cash return on the cash you invested—not the property value.
Cash-on-Cash Formula
Cash-on-Cash = Annual Cash Flow ÷ Total Cash Invested × 100
What Counts as "Cash Invested"?
- Down payment
- Closing costs (buyer side)
- Immediate repairs needed
- Reserves set aside
Cash-on-Cash Example
Purchase Price: $200,000
Down Payment (20%): $40,000
Closing Costs: $5,000
Total Cash Invested: $45,000
NOI: $14,112/year
Mortgage Payment (P&I): $10,800/year
Annual Cash Flow: $14,112 - $10,800 = $3,312
Cash-on-Cash = $3,312 ÷ $45,000 = 7.4%
Target Cash-on-Cash Returns
- Minimum acceptable: 6-8% (competitive with stock market)
- Good: 8-12%
- Excellent: 12%+ (often requires value-add strategy)
Use our Cash-on-Cash Calculator for quick analysis.
DSCR (Debt Service Coverage Ratio)
DSCR measures how well a property's income covers its debt obligations. Lenders use DSCR to qualify investment properties—a key metric for DSCR loans that don't require income verification.
DSCR Formula
DSCR = NOI ÷ Annual Debt Service
DSCR Example
NOI: $14,112/year
Annual Mortgage Payments: $10,800
DSCR = $14,112 ÷ $10,800 = 1.31
DSCR Benchmarks
Below 1.0
Negative cash flow
Won't qualify for DSCR loans
1.0 - 1.25
Marginal coverage
May qualify, higher rates
1.25+
Strong coverage
Best loan terms
Use our DSCR Calculator to check if your property qualifies for DSCR financing.
Putting It All Together: Full Property Analysis
Let's walk through a complete rental property analysis using all five metrics:
Sample Property: 123 Oak Street
Purchase Price
$220,000
Monthly Rent
$1,950
Down Payment
$44,000 (20%)
Loan Rate
7.25%
Step 1: Calculate NOI
Gross Annual Rent: $23,400
Less Vacancy (5%): -$1,170
Less Taxes: -$2,750
Less Insurance: -$1,320
Less Management (8%): -$1,872
Less Maintenance (5%): -$1,170
NOI = $15,118/year
Step 2: Calculate Metrics
Analysis Verdict
This property has a decent cap rate (6.87%) but weak cash flow metrics. The 1.05 DSCR and 1.44% cash-on-cash return suggest the property is overpriced at current interest rates. Either negotiate a lower price or wait for rates to drop.
Quick Screening Rules of Thumb
Before running full analysis, use these quick filters to screen properties:
1% Rule
Monthly rent should be at least 1% of purchase price.
$200,000 property → $2,000/month rent minimum
50% Rule
Operating expenses typically consume ~50% of gross rent.
Quick NOI estimate = Gross Rent × 50%
Gross Rent Multiplier (GRM)
Price ÷ Annual Rent. Lower is better.
Target: Under 10 for cash flow markets
$100/door Rule
Target $100+ monthly cash flow per unit after all expenses.
Accounts for unexpected costs and profit.
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