About AI Fit Hub

Multi-formula transparency. Our TDEE calculator doesn't give you one number from one formula — it runs Mifflin-St Jeor, Harris-Benedict, WHO/FAO, and optionally Katch-McArdle, then shows the range so you know how confident the estimate is.

AI Fitness Coach. Answer 4 questions, get a complete personalized plan: TDEE, calorie target, macros, protein, per-meal breakdown, weekly training/rest split, and a timeline. No guessing which tool to use — the coach routes you through all of them.

Result-aware intelligence. Our tools don't just output numbers — they explain what your specific result means. Low TDEE? We warn about minimum calorie floors. Body fat at 32%? We show what reaching 25% would require. 1RM from 15 reps? We note the estimate is less reliable.

Agent-first API. Every tool has a JSON API that ChatGPT, Claude, and custom agents can call directly. The /api/plan/ endpoint chains multiple tools into a single call for a complete fitness plan.

Works at the gym. The site is a PWA — install it on your home screen and use it offline. No signal needed for plate loading, 1RM calculations, or heart rate zones.

AI Fit Hub is built by Christoph (product, strategy) and Rusty (AI co-founder — builds, tests, and deploys continuously). Part of the Orbyd AI Hub Network.

New here? Start with the AI Fitness Coach — it builds your personalized plan in 60 seconds.

Know what you need? Go to All Tools and search.

Want to learn? Browse 330+ guides, formulas, tips, and comparisons.

Track over time? Save results to your Dashboard — all stored locally in your browser.

Building an agent? See AI Integrations for API endpoints and contracts.

Zero tracking. No cookies, no analytics pixels, no PII collection. Body measurements never leave your browser.

Zero signup. Every tool works immediately. No account walls, no email gates, no "sign up to see your results."

Formula transparency. Every calculator shows which formula it uses and links to the peer-reviewed source. We cite PubMed, not "studies show."

Body-neutral language. Our tools calculate — they don't prescribe goals. "Energy needs" not "calories to lose weight." We show ranges, not judgments.

Not medical advice. Every page includes a health disclaimer. We help you understand your numbers, not diagnose or treat conditions.