Rental Property (Cash Flow) Calculator

Estimate rental cash flow and NOI using vacancy, operating expenses, reserves, and financing. Great for quickly screening a deal before you build a full pro forma.

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Inputs

Operating assumptions (monthly)

Results

Monthly cash flow
-$144
Cap rate (NOI / price)
5.45%
Cash-on-cash (simplified)
-2.76%
Monthly breakdown
  • Effective rent (after vacancy): $1,995
  • Operating expenses (incl. PM): $860
  • NOI: $1,135
  • Mortgage: $1,279
  • Cash flow: -$144

Tip: Add closing costs, rent growth, and appreciation later for a full pro forma.

How to Use This Rental Property Calculator (Mini Guide)

This is a quick underwriting pass to estimate cash flow and NOI using vacancy, reserves, and operating expense assumptions — so you don’t buy “paper cash flow.”

Mini Guide
On this page

What this calculator measures

It estimates: monthly cash flow, NOI (income after operating expenses), and simplified returns.

It’s meant to answer: “Does this deal survive real expenses and still cash flow?”

Inputs that matter most (verify these first)

Market rent (not seller rent): validate with comps.

Vacancy: even great rentals go vacant — 0% is unrealistic.

Taxes + insurance: often change after purchase and vary by location.

Reserves (maintenance/CapEx): prevents ‘cash flow’ disappearing after a roof/HVAC/turnover.

3-minute underwriting workflow

Enter purchase price + financing terms.

Enter market rent + realistic vacancy.

Enter taxes/insurance (or start with defaults, then refine).

Keep reserves non-zero unless you have strong documentation that it’s truly turnkey.

How to interpret the output

If cash flow is barely positive, one repair can flip the deal negative.

NOI helps compare deals across markets. Cash flow tells you if the deal pays you monthly after debt.

For accuracy, treat rehab, closing costs, and initial reserves as part of your cash invested.

Next steps

If it fails: don’t force it — price is likely too high or rent is overstated.

If it passes: stress test vacancy and expenses, then build a fuller 5–10 year model.

Try it with local assumptions

Pick a city:

FAQ

What is NOI?
NOI (Net Operating Income) is income after operating expenses, before debt service (mortgage).
Why use vacancy and CapEx reserves?
They help you avoid overestimating returns by accounting for real-world downtime and long-run repairs like roofs/HVAC.
Is cash-on-cash return accurate here?
This version is simplified (down payment only). Add closing costs, rehab, and reserves for a more precise model.