Open-source fitness tracker

Track. Progress. Evolve.

The open-source training companion for serious lifters — 16 calculators and an evidence-based knowledge base, free and private by design.

Try the Calculators Download App

Free calculators

20+

Evidence-based guides

Accounts needed

MIT

Open-source (MIT)

Why Metri

Everything a lifter needs, free on the web.

No paywalls, no sign-up, no fluff — open-source tools you can actually trust. The app is just an optional extra.

16 instant calculators

1RM, TDEE, macros, body fat, BMI, FFMI, ideal weight, protein, heart-rate zones, Wilks/DOTS and more — each with a visual chart and a shareable link.

BMR & TDEE Macro Splitter 1RM Calculator Body Fat Ideal Weight Heart-Rate Zones

Open the calculators

Open source forever

MIT-licensed and built in the open. Read the formulas, fork it, contribute.

View on GitHub

Works offline

The optional native app runs every tool with zero connection — your data stays on device.

Evidence-based guides

A growing knowledge base on nutrition, training and recovery — written for lifters, not clicks.

Browse the docs

Private by design

Calculators run in your browser. An account is optional and only syncs what you choose to save.

Tools

Calculators & Tools

16 free calculators that run instantly in your browser — the most-used ones first, with the full set a click away.

Popular

1RM Calculator

Estimate your one-rep max (Epley, Brzycki) from any set.

Popular

BMR & TDEE

Estimate daily energy expenditure (Harris-Benedict, Mifflin-St Jeor, Katch-McArdle).

Popular

Macro Splitter

Protein, carbs and fat targets from your calories and goal.

Popular

Body Fat

U.S. Navy circumference method for body-fat percentage.

Popular

Healthy Weight & BMI

Your BMI and the WHO healthy-weight range.

Popular

Ideal Weight

A healthy target weight for your height (Devine, Robinson, BMI range).

FFMI Hydration Plate Calculator Calorie Deficit Protein Intake Lean Body Mass Heart-Rate Zones Waist-to-Height Wilks / DOTS Calories Burned

See all 16 calculators

Docs

Knowledge Base

An evidence-based, bilingual knowledge base — eight sections covering nutrition, training, recovery and more, written for lifters.

Getting started

Welcome to Metri and how to use it.

Calculators

Guides to TDEE, macros, body fat, FFMI, 1RM and hydration.

Nutrition

Macros, calories, meal timing and personalizing your diet.

Training

Progressive overload, volume, frequency, intensity and technique.

Recovery

Sleep, deloads and managing fatigue.

Supplements

What's worth taking — and what isn't.

Progress

Measuring and tracking real progress over time.

Glossary

Plain-English definitions of every key term.

Browse the knowledge base

Free account

Why create an account

Calculators are free for everyone — an account just remembers your work.

Guest

No sign-up needed.

Every calculator, instantly
No account required
Nothing saved between visits

Recommended

Free account

Free forever — no card.

Save your calculation history
Pin favorite calculators & guides
Link Google or GitHub
Sync across the web app

Coming soon

On the roadmap.

Metri mobile app sync
Cloud backup of your data
Cross-device history

Create a free account Sign in

Also on mobile

Prefer your phone? Take it with you.

Everything on Metri is free on the web. A native app is on the way as an optional extra — the same tools, fully offline.

Instant calculators that run on every keystroke
Works 100% offline — your data stays on device
Progress photos and reminders
Free and open source, forever

Metri

Hi, lifter

Daily energy

2,540 kcal

1RM

Macros

FFMI

Water

PowerBuilding

Week 3 · Push day

Built in the open Metri

Metri is MIT-licensed and free forever. Star it, fork it, or contribute on GitHub.

View on GitHub