About

RentalROICalculator is a free, independent tool that estimates the core investment metrics real estate investors use to evaluate a rental property: monthly cash flow, cash-on-cash return, cap rate, and net operating income (NOI). No account, nothing uploaded, no cost for the core calculator.

What it actually does

You enter a property's purchase price, financing terms (down payment, interest rate, loan term), monthly rent, and itemized operating expenses (property tax, insurance, HOA, maintenance, vacancy, property management, and other costs). The tool applies the standard mortgage amortization formula and standard real-estate-investing formulas to compute your monthly mortgage payment, total monthly outflow, monthly and annual cash flow, cash-on-cash return, NOI, and cap rate — plus a simple 5-year projection. Every formula used is documented in full on the how it works section of the homepage.

Who this is for

Individual real estate investors — first-time buy-and-hold landlords sizing up a potential purchase, or existing owners comparing a few candidate properties side by side — who want a fast, transparent, free way to run the numbers on a deal before (or alongside) a full underwriting spreadsheet or a conversation with a lender or agent.

Why we built it

Searching for "rental property calculator" turns up a genuinely fragmented field: older, dated calculator sites; community/education platforms like BiggerPockets where the calculator is secondary to forums and courses; and paid SaaS platforms (Mashvisor, Roofstock) aimed at active portfolio management rather than a one-off "run the numbers on this deal" use case. We saw room for a clean, fast, free, single-purpose tool that gets the math right — including the cap-rate-vs-cash-on-cash distinction that trips up a lot of first-time investors — without a sign-up wall.

What it is not

• It is not financial, investment, tax, or legal advice. See the disclaimer on every page.
• It does not model property appreciation, depreciation tax treatment, refinancing, capital expenditure reserves beyond what you enter as "other," or exact market-specific closing costs — all of which materially affect a real investment decision.
• It is not affiliated with any specific lender, brokerage, or property management company. Figures you enter (interest rate, expense percentages) should reflect your own quotes and research, not generic defaults.

How your data is handled

All calculations happen in your browser — nothing is uploaded to, or stored on, any server. If you use "Save this scenario," that data is written only to your own browser's localStorage. See the privacy policy for full detail.

Contact

Questions or corrections: support@rentalroicalculator.com

→ Run the numbers (free)