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Energy Converter

Convert between joules, calories, kilowatt hours, BTU and more.

1 Kilowatt hour (kWh) =
3,600 Kilojoule (kJ)
Joule (J)
3,600,000
Kilojoule (kJ)
3,600
Megajoule (MJ)
3.6
Calorie (cal)
860,420.6501
Kilocalorie (kcal, food Calorie)
860.4206501
Watt hour (Wh)
1,000
British thermal unit (BTU)
3,412.141633
Foot-pound (ftยทlbf)
2,655,223.737
Electronvolt (eV)
2.246943e+25

What is Energy Converter?

Energy is the ability to do work or produce heat. Electricity bills use kilowatt hours, food labels use calories, heating uses BTU and science uses joules.

What this tool does

Choose the unit you have and the unit you want, then enter a value. The result is shown first, and a table below lists the same value in every other unit of this converter. Factors use the standard definitions, so converting there and back gives the starting value.

How to use it

  1. Enter the value to convert.
  2. Choose the unit to convert from and the unit to convert to.
  3. Read the result, or look in the table for the other units.

Did you know?

  • One kilowatt hour is exactly 3.6 million joules.
  • The food Calorie on a nutrition label is a kilocalorie, which is 1,000 small calories or 4,184 joules.

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