Open Source Calculators
NimbusCalc is an open‑source project providing free, accurate calculators for health, fitness, and daily life. Explore the tools, contribute code, or use them online.
⚡ Quick BMI Calculator (Live Demo)
Enter your height and weight to see your BMI instantly. This is one of our many open‑source tools.
📊 Learn more: Full BMI Calculator with detailed analysis | Body Fat Calculator
Featured Open‑Source Tools
Check out these popular calculators – all available for free on NimbusCalc
Calorie Calculator
Estimate daily calorie needs for weight loss, maintenance, or gain.
Calculate calories →BMR & TDEE
Basal Metabolic Rate and Total Daily Energy Expenditure for diet planning.
Calculate BMR →Why Contribute?
Help build free tools that millions rely on
Modern Tech Stack
HTML5, CSS3, JavaScript – clean, readable code. Perfect for learning or contributing.
Fork on GitHub →Community Driven
Join developers, designers, and health experts to improve over 1198 calculators.
Get involved →Real‑World Impact
Your contributions help people make informed decisions about health, finance, and fitness.