Energy Unit Converter
Convert between all major energy units: Joules, calories, BTUs, electronvolts, watt-hours, and more.
The Ultimate Energy Unit Converter
Our energy unit converter is a comprehensive tool that accurately transforms measurements between all major energy units: Joules (J), calories (cal), kilocalories (kcal), British Thermal Units (BTU), electronvolts (eV), watt-hours (Wh), kilowatt-hours (kWh), ergs, foot-pounds (ft·lb), and therms. This is essential for science, engineering, nutrition, and more.
Get instant, precise conversions for physics, engineering, nutrition, electrical calculations, and everyday energy conversions. Supports decimal inputs and provides results to appropriate decimal places.
Input Energy
Any energy unit
Precise Conversion
Mathematical accuracy
Converted Result
Accurate energy output
Energy Converter
Conversion Formula
Energy Conversion Made Simple
Convert between Joules (J), calories (cal), kilowatt-hours (kWh), BTUs, electronvolts (eV), and more. Whether you're calculating energy needs for your home, working on physics problems, or comparing food energy values, our converter handles all common energy units with precision. Just enter your value and select units - results appear instantly.
Common searches we cover include “Joules to calories,” “kWh to BTUs,” “BTUs to Joules,” “calories to kWh,” and “electronvolts to Joules.” Our clear formulas and interactive table let you verify each conversion step and explore ranges at a glance.
- Instantly switch between metric, imperial, and specialized units
- Precision up to 9 decimal places or scientific notation
- Ideal for science, engineering, nutrition, and everyday use
- Fully responsive, no ads, and respects your privacy