What is METRI?

A quick tour of the open-source fitness toolkit — calculators, programs and a knowledge base.

1 min read

METRI is an open-source fitness companion built for people who actually train. It bundles the tools serious lifters reach for — evidence-based calculators, a structured training engine, and a no-nonsense knowledge base — into one fast, private, ad-free package.

What you get

  • Calculators that run instantly in your browser: 1RM, TDEE, macros, body fat, FFMI, hydration and more. The same formulas power the mobile app.
  • Programs — structured, multi-week routines with per-week prescriptions.
  • A knowledge base like this one: short, practical guides with no fluff.

Everything here is free and open source. The mobile app works fully offline — your data never leaves your device.

Who it's for

Whether you train for strength, hypertrophy, or general health, METRI gives you the numbers without the guesswork — and explains what they mean.

How to use the docs

Start with the calculator guides if you want to understand a specific number, or read the training and nutrition sections to build a mental model. Each article links to the relevant tool so you can go from "what" to "how" in one click.

This is educational content, not medical advice. For anything health-related, talk to a qualified professional.

Educational content only. Not medical advice — consult a professional for your situation.