Calcxi.com, free tools, no sign-up
Every calculator and tool
you actually need.
Finance, business, health, construction, YouTube, Instagram and AI. 30 tools, every formula checked against a named source, all of it free and running entirely in your browser.
Finance
Credit card payoff, savings goal, Mercedes lease and cumulative abnormal return.
4 tools →Business
Valuation, break-even, profit margin and the new markup and job pricing tool.
4 tools →Health
BMI, water intake, heart rate zones, running pace and sleep cycles.
5 tools →Construction
HVAC, air conditioner and furnace replacement costs, plus pine straw coverage.
4 tools →YouTube & SEO
Tag extractor, comment picker, thumbnails, video stats, titles and revenue.
6 tools →Save reels, videos and photos in original quality, with no login and no limit.
3 tools →AI Utilities
Token counters for the ChatGPT and Claude APIs, so you can price a prompt first.
2 tools →Mathematics
Greatest common factor, with the working shown step by step.
1 tool →All Tools 30
Free · Browser-only · No login
Finance
Business
Health
Construction
YouTube & SEO
AI Utilities
Mathematics
New tools are added most weeks. The four marked NEW above went live in the last few weeks. Bookmark this page, or use the search at the top to jump straight to one.
Why these tools stay free
Browser-only calculations. Zero data sent to any server.
Sign-ups required. No account, no email, nothing.
Uses per tool, per person. No rate limits, ever.
Every formula checked against a named source.
Expert Guides
all articles →Business
How to Do a Break-Even Analysis
The number every owner should know before they set a price.
Finance
What is Cumulative Abnormal Return?
How to measure unexpected stock performance around key events.
How the Instagram Algorithm Works
The signals that decide who sees a reel, and the myths that will not die.
How to Download Instagram Reels to Your Phone
Step by step for iPhone and Android, including where the file lands.
YouTube
How to Do a Giveaway on YouTube
Run a fair, policy compliant giveaway from entry to winner.
Data
What Percent of American Men Are Over 6 Feet?
A data backed look at height distribution in the US.
Questions
Are all tools on Calcxi completely free?
Yes, every tool is free with no sign-up, no premium tier and no paywalls. Advertising covers the running costs, which is what keeps the tools free indefinitely.
Does Calcxi store the numbers I enter?
No. All calculations happen inside your browser. Nothing you type is transmitted to our servers, so your financial figures, health data and business numbers never leave your device.
How do I know the results are accurate?
Every formula is taken from a named authoritative source, such as NIH research, ASHRAE standards, IRS guidance, state statutes or published accounting references, and each tool carries a Last Updated date. The accuracy policy sets out exactly how that verification works.
Which tools should a small business owner start with?
The four tools in the Business section answer the questions owners ask most. Break-even tells you the sales volume that covers your costs, profit margin tells you how much of each sale you keep, markup tells you what to charge, and valuation gives you a defensible range for what the company is worth.
Do the Instagram and YouTube tools need an account?
No. The Instagram downloaders and the YouTube tools read what those platforms already show to anyone with the link, so there is nothing to log in to. That is also why they only work on public posts and public videos.
Can I request a new calculator?
Yes. Use the contact page or email support@calcxi.com. Most new tools on the site started as a user request.
Do the tools work on mobile?
Yes. Every tool is responsive and tested on phones and tablets, and number fields open the numeric keypad automatically on touch devices.
How often are the tools updated?
Cost and rate driven tools are reviewed whenever their underlying source data changes, and formula driven tools are re-checked against their source whenever that source is revised. The Last Updated date on each page reflects the most recent review, not the publish date.