What is Rental Property Cash Flow Calculator?
The Rental Property Cash Flow Calculator helps investors analyze the profitability of rental properties.
When to Use This Calculator
- Underwriting a rental property purchase before making an offer
- Comparing multiple rental candidates side by side on cash flow and cash-on-cash return
- Deciding how large a down payment to put down based on its effect on monthly cash flow
- Stress-testing a property against a vacancy period or a maintenance-heavy year
- Checking whether a rent increase meaningfully improves the property's return
- Explaining a rental's full financial picture to a lender, partner, or spouse before buying
Steps:
- Enter purchase price and down payment.
- Input interest rate and loan term.
- Add monthly rent and expenses.
- View cash flow and returns.
Formula
Monthly Cash Flow = Effective Rent − Total Expenses
Effective Rent = Monthly Rent × (1 − Vacancy Rate / 100)
Total Expenses = Mortgage + Monthly Expenses + Property Tax / 12 + Insurance / 12 + Maintenance / 12
Mortgage = P × [r(1+r)^n] / [(1+r)^n − 1]
Where: P = Loan Amount, r = Monthly Interest Rate, n = Total Payments
Cash-on-Cash Return = (Annual Cash Flow / Down Payment) × 100
Cap Rate = (NOI / Purchase Price) × 100
NOI = (Effective Rent × 12) − Annual Operating Expenses
Use Cases
- Property analysis
- Investment comparison
- Portfolio planning
Key Benefits
- Get accurate rental property calculator results instantly
- Save time with rental property calculator calculations
- Make informed decisions with clear data
- Free on any device no downloads
Pro Tips
- Double-check inputs for accuracy
- Run multiple scenarios
- Combine with other tools
Common Mistakes to Avoid
- Using inaccurate inputs
- Ignoring key factors
- Misinterpreting outputs
Key Terms Explained
- Input: Values you provide
- Output: Results computed
- Formula: Method used
- Result: Calculated answer
Related Concepts
- Cap Rate: Cap rate isolates the property's return from your specific financing, which makes it the number to use when comparing rentals bought with different loan terms. Our cap rate calculator pulls this out on its own.
- Cash-on-Cash Return: While this calculator shows cash-on-cash return as one of its outputs, our dedicated cash-on-cash return calculator is useful for quickly testing how different down-payment amounts change your percentage return.
- DSCR: Before a lender approves financing, they'll check whether the property's NOI clears their minimum debt service coverage ratio — verify that separately with our DSCR calculator.
- NOI: Net operating income is the foundation this calculator's cap rate and other figures are built on — our NOI calculator is useful when you want to isolate and double-check that number on its own.
- Rent vs Buy: If you're weighing whether to buy this property to live in rather than rent it out, that's a different decision with a different calculator — see our rent vs buy calculator for the owner-occupied comparison.
Example
A $300K property with 20% down, 6.5% rate, $2K rent, and $500 expenses generates positive cash flow.
Interpreting Your Results
This calculator combines financing, income, and expenses into the four numbers that matter most for a rental purchase: monthly cash flow (what's left after the mortgage and all expenses), cash-on-cash return (return on the cash you invested), cap rate (return on the full purchase price, independent of financing), and NOI (the property's pure operating income). Positive monthly cash flow with room to spare is the baseline test — a property that only breaks even has zero cushion for a vacancy, a repair, or a rate increase on a variable loan. Cap rate is the number to use when comparing properties across different financing scenarios, since it ignores your loan terms entirely; cash-on-cash is the number to use when comparing how efficiently your actual cash is being deployed. Run the numbers again with a lower rent and a higher vacancy rate than you expect — if the property still cash-flows under that more conservative scenario, it has real margin for error; if it doesn't, you're relying on everything going right.