About this tool
Rental Cap Rate Calculator is a free deal analyzer for residential real-estate investors. Enter a property's price, rent, operating expenses, and financing, and it returns the metrics investors actually underwrite with: capitalization rate, net operating income, cash-on-cash return, debt service coverage ratio (DSCR), monthly and annual cash flow, gross rent multiplier, return on investment, and a multi-year projection — all on one page.
We built it because the calculators that rank for "cap rate calculator" do one thing each: they compute a single number and stop. Almost none can analyze a financed deal, show you DSCR the way a lender does, or tell you in plain English whether the numbers look reasonable. The genuinely comprehensive tools tend to hide behind an account, an email wall, or a monthly subscription after a few free reports. We wanted the opposite: every metric, unlimited use, no account, no email, and no upsell.
Correctness is the whole point
A deal calculator is only useful if the math is right, so we treat the formulas as the product. Every metric is implemented in a single, typed calculation module that is covered by unit tests, and each formula and convention was cross-checked against multiple independent, authoritative real-estate sources before we shipped it. We deliberately lock the conventions that calculators most often get wrong — for example, cap rate is computed unlevered (net operating income never subtracts your mortgage), vacancy is modeled as a reduction of income rather than an expense, and capital-expense reserves sit below the NOI line so the headline cap rate stays comparable to market comps. The methodology section on the home page shows each formula and the reasoning behind it.
Private by design
Every calculation runs locally in your browser. The numbers you type are never uploaded to a server, there is no account to create, and there is no limit on how many deals you analyze. You can copy a shareable link that encodes your inputs so you can revisit or send a scenario, but that link lives only wherever you choose to paste it.
This is an independent educational tool, not a brokerage, lender, or advisory service, and nothing here is financial, investment, tax, or legal advice. Real returns depend on assumptions, financing terms, taxes, and market conditions a calculator cannot know. Always verify figures and consult a qualified professional before acting. Found an error or have a feature request? Our contact page is the fastest way to reach us.