Why this site exists
We built this after testing the free calculators that already existed: most wanted something before they would show an answer (an email, an account, or a few minutes on a call with a broker). So this site answers instantly, is free, and stays free. The arithmetic runs entirely in your browser, and there is no signup, no email, and no account. Every number is explained with its formula and a worked example. It is written for U.S. real estate investors, from a first duplex to a small portfolio.
Twelve calculators cover the full deal lifecycle, from cap rate and NOI through the BRRRR strategy, a full fix-and-flip cost model, a mortgage payment tool for buyers, and a prorated rent tool for tenants and landlords.
New to real estate math? The Learn hub collects plain-English guides to every metric, categorized into Getting Started, Metric Guides, Strategies, and Advanced Topics.
Who's behind it
We are a small, independent team with no lender, brokerage, or property manager behind the site. Nothing here recommends a product, captures a lead, or sells your attention. The goal is narrower than that: give every investor the same arithmetic a commercial underwriter runs, in a page that loads instantly and still works on a phone with no signal. Reach us at hello@freecapratecalculator.com.
How the math and content are maintained
Every metric here uses a standard formula: net operating income = gross rent − operating expenses; cap rate = NOI ÷ purchase price; cash-on-cash = annual cash flow ÷ cash invested; DSCR = NOI ÷ annual debt service; mortgage payments by the standard amortization formula. Each calculator page states its formula in plain language, walks a worked example, and carries the date it was last reviewed, so you can check the arithmetic yourself instead of trusting a black box. Benchmark ranges (for instance, the 6–10% net yield convention on residential rentals) reflect widely cited underwriting practice, not proprietary data.
The site is organized into three sections. The calculators cover twelve metrics, strategies and rental tools, each with a full guide and worked examples. The Learn hub collects the educational content by category. The About and Contact pages cover the site itself.
What to run first
Start with the cap rate calculator to see what the building earns per dollar of price. Work the expense side with net operating income before trusting that yield. Before you talk to a lender, run the DSCR screen to see whether the rent covers the note. For strategies beyond the basics, the BRRRR calculator and the fix and flip calculator extend the same math to those exits.
The homepage calculator puts every core metric on one screen with live recalculation, which is the fastest way to compare two deals.
What happens to your data
The calculators collect no data. Each one is static HTML plus JavaScript that runs entirely in your browser, so there is no backend to send numbers to. Saved compare-deals live in your browser's localStorage and disappear when you clear it. Site analytics use Google Analytics for aggregate traffic measurement only. No user inputs to the calculators ever leave your browser. The privacy policy spells it out in full.
One caution to keep the relationship honest: the deal grade and the benchmark bands are educational approximations. They omit taxes, financing variety, local regulation, and your own risk tolerance. Verify every number against real comps and licensed professionals before you transact.