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Energy Unit Converter

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

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Common Conversions

FromJcalBTU
1000 J1000239.0060.947813
1 kWh36000008604213412.13
100 cal418.41000.396565
1 BTU1055.06252.1651

About Energy Unit Converter

Convert between energy units including joules (J), kilojoules (kJ), calories (cal), kilocalories (kcal), kilowatt-hours (kWh), and British Thermal Units (BTU). One kilowatt-hour equals 3,600,000 joules, and one food calorie (kcal) equals 4,184 joules. Useful for physics, nutrition, and energy consumption calculations.

How to Use Energy Unit Converter

  1. 1

    Enter an energy value

    Type the energy amount in the unit you want to convert from.

  2. 2

    Select your unit

    Choose the source unit from the dropdown (joules, calories, kWh, BTU, etc.).

  3. 3

    Read the conversions

    All equivalent energy values in other units appear instantly.

Common Use Cases

  • Physics and engineering homework and calculations
  • Comparing food energy (calories) to physical units
  • Calculating electricity consumption in joules or BTU
  • Understanding heating and cooling system energy ratings

Frequently Asked Questions

How many joules are in a kilowatt-hour?
One kilowatt-hour (kWh) equals exactly 3,600,000 joules (3.6 MJ).
How many calories are in a joule?
One joule equals approximately 0.239 calories (small calories). One food calorie (kilocalorie/kcal) equals 4,184 joules.
What is a BTU?
A BTU (British Thermal Unit) is the amount of energy needed to raise 1 pound of water by 1°F. One BTU equals approximately 1,055 joules.

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