Rental Property Analysis: How to Calculate Cash Flow and ROI
Why Rental Property Analysis Matters
Buying a rental property without running the numbers is gambling, not investing. A property that looks like a good deal can bleed cash every month if the math doesn't work.
This guide covers the essential metrics every rental investor must know.
The 5 Key Rental Property Metrics
1. Monthly Cash Flow
The simplest and most important number:
Cash Flow = Rental Income - All Expenses
Expenses include:
A good rental property should produce at least $200-$300/month in positive cash flow per unit.
2. Cap Rate (Capitalization Rate)
Cap rate measures the return on a property independent of financing:
Cap Rate = Net Operating Income (NOI) / Purchase Price x 100
NOI = Annual Rental Income - Annual Operating Expenses (excluding mortgage)
| Cap Rate | What It Means |
|---|---|
| 4-6% | Low return, typically appreciation markets (coastal cities) |
| 6-8% | Moderate return, balanced markets |
| 8-10% | Strong return, cash flow markets |
| 10%+ | High return but may indicate higher risk |
3. Cash-on-Cash Return
Measures the actual return on the cash you invested:
Cash-on-Cash = Annual Cash Flow / Total Cash Invested x 100
Total cash invested includes:
Target: 8-12% cash-on-cash return is considered strong.
4. The 1% Rule
A quick screening tool:
Monthly rent should be at least 1% of the purchase price.
Properties meeting the 1% rule are more likely to cash flow, but always run the full analysis.
5. Debt Service Coverage Ratio (DSCR)
Used by lenders to evaluate rental loans:
DSCR = Net Operating Income / Annual Mortgage Payments
Real Example: Rental Property Analysis
Property: 3BR/2BA single-family home
| Item | Amount |
|---|---|
| Purchase Price | $180,000 |
| Down Payment (25%) | $45,000 |
| Closing Costs | $5,000 |
| Monthly Rent | $1,800 |
| Mortgage (P&I) | $900/mo |
| Property Tax | $200/mo |
| Insurance | $100/mo |
| Management (10%) | $180/mo |
| Maintenance (8%) | $144/mo |
| Vacancy (5%) | $90/mo |
This deal is borderline. A lower purchase price or higher rent would improve the numbers significantly.
Common Rental Analysis Mistakes
1. Forgetting Vacancy
No property is rented 100% of the time. Always account for 5-8% vacancy.2. Ignoring Maintenance
Budget 5-10% of rental income for maintenance. Older properties need more.3. Underestimating Insurance
Get actual insurance quotes — don't guess. Flood zones and certain property types cost significantly more.4. Not Accounting for CapEx
Capital expenditures (roof, HVAC, water heater) are separate from regular maintenance. Budget an additional 5% for CapEx reserves.Analyze Rental Properties with PropertyARV
PropertyARV helps you make data-driven rental investment decisions:
