Rental Property Calculator
A rental deal on one screen: mortgage, taxes, insurance, vacancy, upkeep and management against the rent — monthly cash flow, NOI, cap rate and cash-on-cash return together.
Four verdicts on one property
A rental deal can be judged four ways at once — monthly cash flow (can I hold it?), NOI (what does the property itself earn?), cap rate (how is it priced against its income?), and cash-on-cash (what does my actual cash earn?). A deal that passes one test and fails another is telling you something specific; this page runs all four on the same inputs.
NOI = (rent − vacancy − upkeep − management) × 12 − taxes − insurance · Cash flow = rent − mortgage payment − all monthly costs
Example: a $250,000 rental at $1,800 a month, 20% down at 7%: mortgage $1,330; taxes, insurance, vacancy and upkeep about $660 — cash flow is roughly −$190 a month despite a respectable 5.6% cap rate. Leverage turned a fine property into a monthly bill; the page exists so the discovery happens before the purchase.
The allowances are not pessimism
Vacancy, maintenance and management percentages are the costs landlords forget in year one and meet in year two. Even self-managing landlords should charge the management line — otherwise the 'return' is partly a wage for unpaid work wearing an investment costume.
How this is calculated
NOI excludes the mortgage (by definition) and includes vacancy, maintenance and management as percentages of rent, plus taxes (price × your rate) and insurance. Cash flow subtracts the amortized mortgage payment from what remains. Cap rate = NOI ÷ price; cash-on-cash = annual cash flow ÷ (down payment + closing). Capital expenditures (roofs, HVAC) sit beyond these allowances — serious underwriting adds a reserve line; treat a thin positive result as negative.
Frequently asked questions
What cap rate is 'good'?
It prices risk and growth expectations locally: 4% in a supply-starved coastal market, 9%+ where rents are high against cheap prices. Compare against your market's going cap for similar properties — and against the mortgage rate, since buying below your borrowing rate means leverage works against you.
Why charge myself management if I self-manage?
Because the investment should be judged as an investment. If the deal only works with free management, part of the 'return' is your labor income — fine, but know which part.
Does cash flow include principal paydown?
No — cash flow is cash. Principal paydown is real wealth-building but arrives as equity, visible in the balance, not the bank account. The page keeps the two honest by keeping them apart.
What's the 1% rule and should I use it?
Monthly rent ≥ 1% of total price is a crude screen from higher-rate eras; in low-rate, high-price markets almost nothing passes and in cheap markets everything does. Run the full page instead — it takes a minute longer and answers the actual question.
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