Energy Converter
Convert joules, watt-hours, calories, BTU, electronvolts, therms, and foot-pounds with formulas and copy-ready output.
Enter an energy amount, choose the source and target units, and generate a copy-ready conversion. The calculation stays in your browser and uses joules as the shared reference value for SI, electrical, food-energy, heat-energy, and mechanical work units.
Use a non-negative number. Commas as thousands separators and scientific notation are accepted.
How it works
The converter first expresses your input in joules, then divides by the target unit energy. Kilojoules and megajoules are decimal SI multiples. Watt-hours use the relationship between watts, seconds, and joules, so 1 kilowatt-hour equals 3,600,000 joules.
Food calories use the thermochemical calorie relationship of 4.184 joules per calorie, with kilocalories equal to 1,000 calories. International Table BTU, US therms, electronvolts, and foot-pounds use standard reference values suitable for quick engineering, utility, classroom, and comparison work.
This tool is for deterministic unit conversion, not metering, billing, nutrition labeling, or regulated engineering certification. Confirm the required legal or domain-specific unit definition when a safety-critical or contractual result depends on it.
