Guides & Insights
Plain-English breakdowns of the numbers behind real estate deals — with the calculators to run them yourself.
What Is a Good Cap Rate for Rental Property?
The honest answer is "it depends" — but here are the real 2026 ranges, and how to know if a deal is actually good.
StrategyThe 70% Rule for House Flipping, Explained
The one-line formula that keeps flippers from overpaying — plus when to bend it and when it will burn you.
StrategyThe BRRRR Method: A Step-by-Step Guide
Buy, Rehab, Rent, Refinance, Repeat — how to recycle the same down payment into a whole portfolio, and where it goes wrong.
FinancingHow Much House Can You Really Afford?
The 28/36 rule, what lenders actually check, and why the number they approve isn’t the number you should spend.
FinancingHow to Get Rid of PMI (and Stop Overpaying)
The 80% request, the 78% automatic drop, and the appraisal trick that can kill PMI years early.
AnalysisWhat Is a Good Gross Rent Multiplier?
The fastest screen in rental investing — the typical 4–12 ranges, and why the national average is useless.
AnalysisThe 1% Rule and 50% Rule for Rentals
Two ten-second gut-checks every landlord quotes — how they work, and why they fail in half the country.
FinancingHow Mortgage Payments Actually Work
PITI, amortization, and why your early payments are almost all interest — explained in plain English.
FinancingWhen Does Refinancing Make Sense?
Forget the old 1% rule — in 2026 the only number that matters is your break-even point.
FinancingWhat Is a DSCR Loan? A Guide for Investors
The loan that qualifies your property instead of you — how DSCR works and what lenders want in 2026.
StrategyCost Segregation Explained (and Why 2026 Is Huge)
The tax strategy that front-loads depreciation — now supercharged by permanent 100% bonus depreciation.
StrategyWhat Is a 1031 Exchange? The 45/180-Day Rules
How to sell an investment property and defer the capital gains tax entirely — if you hit two unforgiving deadlines.
Closing & STRHow to Calculate Airbnb Income (ADR, Occupancy, RevPAR)
The three numbers that predict what a short-term rental will actually earn — and the 2026 benchmarks to judge them against.
About REI Calc
REI Calc is a free suite of 25 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 ([email protected]) 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.