About RentalRundown
RentalRundown exists to answer one question before you buy a rental — is this actually a good deal? — for free, with no signup, no paywall, and no black box.
Why we built it
When you find a property on a listing site, analyzing it is more frustrating than it should be. Full-featured software wants a subscription. The big community tools hide their calculator behind an account. And many of the free calculators do little more than "rent minus the mortgage" — quietly ignoring vacancy, maintenance, and the capital reserves that actually decide whether a rental makes money.
We wanted something different: an honest analysis anyone can run in a minute, that includes the costs beginners forget, and that ends in a real decision — buy, negotiate, investigate, or pass — plus the most you should pay to hit your targets.
How we keep the numbers honest
Trust is the whole point, so we built for it:
- Deterministic math, not a black box. Every result comes from standard, published real-estate formulas. The same inputs always produce the same output, and each metric is computed in exactly one place, so our pages can never disagree with each other.
- Checked by an automated test suite. The calculation engine is backed by tests that independently re-derive every number from scratch — so a silent calculation error can't slip through unnoticed.
- Every assumption is visible and yours. Nothing is hidden. You can edit any input, and figures we estimate — like a default tax rate — are clearly flagged so you know exactly what to verify.
- AI never touches the arithmetic. Where we use it at all, it only helps explain results in plain language. It never computes or changes a number.
You can read exactly how each figure is calculated — the formulas, conventions, and default assumptions — on our methodology page.
Independent, and free for a reason
RentalRundown is an independent project — not owned by, or affiliated with, any lender, brokerage, or listing site. That independence is why we can stay unbiased: we're not trying to steer you toward a particular loan or property.
And we keep it genuinely free. The calculators run entirely in your browser, we don't require an account, and we don't sell your data. The full analysis, the verdict, and the maximum offer price are free, always.
What we're not
We're a tool for thinking clearly, not a substitute for professionals. RentalRundown provides educational estimates, not investment, tax, legal, or financial advice. Property taxes, insurance, rents, and local regulations vary widely — verify every figure independently and consult licensed professionals before you make an offer. See our financial disclaimer.
Get in touch
Questions, corrections, a formula you think we got wrong, or a tool you wish existed? We read everything and use it to make the site better.
Last reviewed August 2026.