DEV3 Free BMI and Calorie Calculator — Source Code (React + Tailwind)

Source code of the DEV3 BMI and Calorie Calculator, a BMI, BMR (Mifflin-St Jeor), TDEE and macro calculator with metric and imperial units and a health disclaimer.

Free download: sign in to any DEV3 account and click Download ZIP. Try it live: https://dev3.tech/tools/bmi-calorie-calculator shows the finished tool running.

What is in the download

• A standalone Vite + React + TypeScript + Tailwind CSS project: src/tool holds the tool, shared pieces sit beside it
• package.json with exact versions plus a lockfile, so npm ci works
• README.md (run, build, embed in Next.js or plain React) and an MIT LICENSE

What the code does

• BMI with category scale and healthy weight range
• Mifflin-St Jeor BMR and five activity factors
• Goal-based calorie target with safety floors
• Protein, carb and fat gram targets

Tech stack

React 19, TypeScript, Vite, Tailwind CSS 4.

Install and customise

The How to install and How to use tabs list the steps. In short: unzip, npm ci, npm run dev, then copy the tool folder into your own app if you want to embed it.

Good to know

• A browser-only tool: there is no backend or database in the code.
• General information only; not a medical tool and not suitable for children or pregnancy.