Method
Energy values are converted through standard factors between joules, calories, watt-hours, BTU, and related units.
Converters / browser tool
Energy Converter
Convert between joules, calories, kilowatt-hours, BTU, and more.
Thermochemical calories and International Table BTU — clearly labelled.
Your inputs stay on your device
Convert energy
live resultConverted value
1 Kilojoule (kJ) = 0.2390 Kilocalorie (kcal)
Calories are thermochemical (1 cal = 4.184 J exactly). Food Calories shown on packaging are kilocalories (kcal).
Context & Reference
How it works
Calculators are most useful when their assumptions are clear. Review these details to better understand the logic behind the results.
How to use it
Enter an energy amount, choose its unit, and compare the labelled equivalents.
Understand the result
Outputs represent the same quantity of energy; prefixes such as kilo and mega change scale.
Example
1 kilowatt-hour equals 3.6 megajoules.
Notes
Calories and BTU have formal definitions; the labels identify which convention the tool uses.
Useful next steps
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