Conversion Calculators
Energy Converter
Convert energy between joules, kilojoules, calories, kilocalories (food Calories), watt-hours, kilowatt-hours, and BTU.
Quick guide
Enter a value and choose the units to convert between joules, kilojoules, calories, kilocalories (food Calories), watt-hours, kilowatt-hours, and BTU. Every conversion goes through joules.
Read the full explanationHow It Works
Energy units span physics (joules), nutrition (kilocalories — the “Calories” on food labels), and utilities (kilowatt-hours). All convert through joules.
Formula Used
value × from-factor ÷ to-factor (base unit: joule).
Example Calculation
1 food Calorie (kcal) = 4.184 kJ; 1 kWh = 3.6 MJ ≈ 860 kcal.
Practical Use Cases
- Convert food energy between kcal and kJ.
- Understand electricity bills in kWh.
- Compare heating values in BTU.