Clear math for better rental decisions.

Why this site exists

Rental property analysis is often split between two extremes: a simple gross-rent multiplier that hides the expenses, or a spreadsheet with enough rows to make the assumptions disappear. We wanted a middle path — a calculator that is fast enough to use during a first look but transparent enough to show the NOI, basis, and target return behind the headline.

The site starts with the questions that frame most rental deals: what does the property yield before financing, what cash flow does it produce after financing, what return does the cash invested earn, and how much cash is still in the deal after a refinance? The cap rate calculator handles the first. The rental cash flow calculator adds debt service, cash-on-cash return, DSCR, a five-year outlook, and reverse solves for rent and price. The cash-on-cash calculator goes deeper on the equity return with all-in cash invested, leverage spread, a break-even interest rate, financing scenarios, and a CoC projection. The hard money calculator sizes a short-term rehab loan from the LTC and ARV caps, separates the initial advance from the rehab holdback, and prices points, interest, fees, cash to close, exit profit, ROI, and break-even. The DSCR calculator tests lender coverage, solves the maximum loan and rent needed, compares amortizing and interest-only payments, and separates the lender ratio from investor cash flow. The BRRRR calculator connects the buy, rehab, rent, and refinance cycle, including hard-money carry, cash left in the deal, post-refi DSCR, ARV stress, and reverse solves. Each one uses the same principle: show the inputs, show the math, and make the limits clear.

Editorial standards

The calculator and guides are produced by the Rental Property Math editorial team. We do not publish invented author biographies, fake credentials, or borrowed testimonials. When a guide relies on a primary source, we link to it. When a range is illustrative rather than sourced, we say so.

• Use standard income-property conventions and disclose when the calculator departs from them.
• Prefer primary sources such as the IRS, HUD, and standard appraisal references.
• Separate education from personalized advice.
• Correct errors and note material methodology changes.
• Do not use fear-based lead capture or fake urgency.

What this site is not

Rental Property Math is not a lender, brokerage, property manager, tax adviser, attorney, or investment adviser. We do not provide personalized investment recommendations, appraisals, or legal opinions. The calculators produce estimates from the inputs you provide. They cannot verify the rent, taxes, insurance, condition, title, zoning, or financing of a property.

Before making an acquisition, verify the numbers with qualified local professionals and your own due diligence. A calculator result is a starting point, not a substitute for a property inspection, a title review, or a loan estimate.

Privacy and independence

The calculators run in your browser. Saved deals and comparisons use local storage on your device. Share links encode the inputs in the URL rather than storing them on a server. There is no account and no server-side deal database. At launch, the site does not use analytics or advertising trackers.

The site is supported by its own resources at launch. If advertising, affiliate links, or sponsorships are added later, they will be disclosed clearly and will not change the methodology or the editorial conclusions. Read the privacy policy for the full data description.

Contact and corrections

Questions, corrections, and source suggestions are welcome at hello@rentalpropertymath.com or through the contact page. Include the page and the specific issue. For a calculation correction, include the inputs, the result you expected, and a reference if one is available.

Updates

The current site and calculator version is 1.5. This page was last reviewed on Oct 28, 2026. Material changes to the calculator formula or expense conventions will be documented on the methodology page.