This rental property calculator runs a full deal: purchase and loan, rent and operating expenses, then reports monthly cash flow, NOI, cap rate and cash-on-cash return.
| Monthly mortgage (P&I) | – |
| Monthly NOI (before debt) | – |
| Monthly cash flow | – |
| Cap rate | – |
| Cash-on-cash (on down payment) | – |
Defaults are deliberately 2020s-realistic: at 7% money, thin cash flow is the market’s current personality, not a spreadsheet error. Add 3–5% closing costs to your cash-in for exact cash-on-cash; this view uses the down payment (noted on the row) for speed.
The Deal in One Screen: Rent In, Everything Out
The yield shorthand behind it all is our Cap Rate Calculator. Part of our Finance Calculators collection.
Worked Example (Verified)
- $300,000 purchase, 20% down, 7%/30-yr loan ($240,000 → $1,596.73/mo), rent $2,600: expenses = vacancy $130 + tax $312.50 + insurance $150 + maintenance $200 → NOI $1,807.50/mo, cap rate 7.23%, cash flow +$210.77/mo, cash-on-cash 4.21% (on the $60,000 down payment)
- The 1% rule autopsy: rent/price here = 0.87% monthly — near the old heuristic, yet cash flow is a modest $211 because 7% debt eats what 3% debt used to leave behind; heuristics don’t survive rate regimes
- Sensitivity: +$200 rent (→ $2,800) lifts cash flow to ≈ +$401/mo and cash-on-cash to ≈ 8.0% — small rent deltas carry deals, which is why rent comps deserve more diligence than granite choices
Underwriting Honesty
- Always carry vacancy (5%+), maintenance and a CapEx reserve (roofs and HVAC amortize whether you budget them or not — add $200–300/mo mentally).
- Management costs money even self-managed: your hours are an expense wearing a disguise; 8–10% of rent is the market price of the disguise removed.
- Cash flow is year one only; rent growth, appreciation, amortization and tax shelter compound quietly off-screen — total-return analysis (IRR) is the sequel.
- Insurance and taxes are the fastest-growing expense lines of the 2020s: underwrite them at renewal quotes, not last year’s bills.
Related Tools
- Cap Rate Calculator — NOI/value yield
- Mortgage Calculator — payment & amortization
- Finance Calculators — the full collection
Frequently Asked Questions
How do you analyze a rental property?
Start with effective rent (rent minus vacancy), subtract operating expenses (tax, insurance, maintenance, management) for NOI, then subtract the mortgage payment for cash flow. Divide NOI by price for cap rate, and annual cash flow by cash invested for cash-on-cash. This calculator runs the whole chain; the defaults produce NOI $1,807.50/mo, 7.23% cap and +$210.77/mo cash flow.
What is the 1% rule and does it still work?
Monthly rent ≥ 1% of purchase price was a quick screen from cheaper-money eras. At 7% rates a property can pass the 1% rule and still cash-flow thin (the defaults do: 0.87% ≈ passing, $211/mo actual). Use it to reject obvious losers fast, never to approve a purchase.
What expenses do landlords forget?
Vacancy between tenants, turnover costs (paint, cleaning, listing), CapEx reserves for roof/HVAC/water heater, management (even if it’s you), and tax/insurance inflation. The forgotten five routinely consume 30–45% of gross rent across a holding period — the gap between spreadsheet deals and real ones.
Is positive cash flow the only goal?
No — loan paydown (amortization), appreciation and depreciation tax benefits are real return streams; some investors accept thin cash flow for them in high-growth markets. But negative cash flow means writing a check monthly for the privilege — underwrite that consciously, with reserves, or not at all.
How much down payment do rental loans need?
Typically 20–25% for investment properties (more than owner-occupied), at rates ~0.5–1 point above primary-home mortgages. The defaults use 20% down at 7% — adjust to your lender’s actual quote before trusting the output.
Is this rental property calculator free?
Yes — free, instant, no sign-up.