Run the numbers on any real estate deal in seconds
The calculators serious property investors actually use — from mortgage payments and cap rates to Airbnb income and the 70% flip rule. Free, instant, and private.
Choose a calculator
Every tool updates instantly as you type and explains the math beneath it.
Why investors use these numbers
Smart real estate investing comes down to a handful of metrics. Cap rate and cash-on-cash return tell you whether a rental produces enough income. ROI captures the full picture — cash flow, appreciation, and loan paydown together. For flips, the 70% rule keeps you from overpaying, and for short-term rentals, occupancy and nightly rate drive everything.
These calculators give you fast, honest answers before you ever make an offer. Bookmark the ones you use most, and always confirm assumptions like rents, expenses, and comparable sales with local data.
Guides & Insights
Plain-English breakdowns of the numbers behind real estate deals — with the calculators to run them yourself.
About REI Calc
REI Calc is a free suite of 21 real estate investment calculators built for the people who actually run the numbers on deals — landlords, house flippers, short-term rental hosts, wholesalers, and buy-and-hold investors.
Why we built it
Most real estate math lives in messy spreadsheets or behind sign-up walls. We wanted a single, fast, private place to answer the questions investors ask before every deal: What's the cap rate? Does this cash-flow? Is the flip worth it at this price? How much equity can I pull with a HELOC? Every calculator gives you an instant answer and explains the formula beneath it, so you learn the math as you use it.
Who's behind it
REI Calc is run by a hands-on property investor based in Springfield, Missouri, who manages short-term and long-term rentals. The tools reflect real workflows used to evaluate, finance, and operate income properties — not textbook theory. As the site grows we're adding guides, worked examples, and market insights to help newer investors make confident, numbers-first decisions.
How it works
Everything runs in your browser. You type in your numbers, the calculator updates instantly, and nothing you enter is stored or sent anywhere. There's no account to create and no cost — the site is supported by advertising so the tools can stay free for everyone.
A note on accuracy
REI Calc provides estimates for educational purposes only and does not constitute financial, tax, legal, or investment advice. Formulas follow standard industry conventions, but real-world costs, taxes, rates, and returns vary. Always confirm your assumptions and consult a qualified professional before making a real estate decision.
Questions or feedback? Get in touch — we read every message.
Contact us
Have a question, spotted a bug, or want to suggest a calculator we're missing? We'd love to hear from you.
The fastest way to reach us is by email:
Set up this inbox on your domain (hello@crunchrei.com) so messages reach you — most registrars and email hosts let you add it in a few minutes.
What to include
- Feature requests — tell us which calculator you'd like added and how you'd use it.
- Corrections — if a formula or result looks off, send the inputs you used so we can reproduce it.
- Partnerships & advertising — reach out if you'd like to work with us.
We typically reply within a couple of business days.
Privacy Policy
Last updated: July 2026. This policy explains what information REI Calc collects, how it's used, and the choices you have.
The short version
The numbers you type into our calculators are processed entirely in your browser. We do not store, transmit, or have access to the figures you enter. We do use standard web analytics and advertising services, which are described below.
Information we collect
Calculator inputs: None are collected. All calculations run locally on your device and are never sent to our servers.
Usage data: Like most websites, we may collect anonymous, aggregated information such as pages visited, browser type, device type, referring site, and general location (country/region). This helps us understand which tools are useful and improve the site.
Cookies and similar technologies: We and our partners use cookies and similar technologies to remember preferences (such as light/dark mode), measure traffic, and serve advertising.
Advertising and third parties
This site is supported by advertising. We plan to use third-party ad networks, including Google AdSense. Third-party vendors, including Google, use cookies to serve ads based on your prior visits to this and other websites.
- Google's use of advertising cookies enables it and its partners to serve ads to you based on your visit to this site and/or other sites on the internet.
- You may opt out of personalized advertising by visiting Google Ads Settings.
- You can also opt out of third-party vendor cookies for personalized advertising at www.aboutads.info.
- For more on how Google uses data, see Google's policy.
Analytics
We may use privacy-respecting analytics services to measure aggregate traffic. These services do not identify you personally.
Your choices
You can disable cookies in your browser settings, though some features (like remembering dark mode) may not work as expected. You can opt out of personalized ads using the links above.
Children's privacy
This site is intended for adults and is not directed at children under 13. We do not knowingly collect personal information from children.
Data for users in the EU, UK, and California
Depending on your location, you may have rights under laws such as the GDPR or CCPA, including the right to access or delete personal data and to opt out of the sale or sharing of personal information. Because we do not collect personally identifiable information directly, most requests relate to cookies set by our advertising and analytics partners, which you can manage using the opt-out links above. Contact us with any questions.
Changes to this policy
We may update this policy from time to time. Material changes will be reflected by the "last updated" date above.
Contact
Questions about this policy? Contact us here.