Energy Converter

Convert between different energy units instantly. Accurate conversions for joules, calories, watt-hours, kilowatt-hours, BTU, electronvolts, and more.

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Energy Value 1
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From Unit Kilojoule (kJ)
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To Unit Kilocalorie (kcal)
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Common Conversions Quick Convert
Quickly convert common energy units
1
Kilojoule
(kJ)
0.239
Kilocalorie
(kcal)
1 kJ = 0.239006 kcal
Conversion Rate
1 kcal = 4.184 kJ
Inverse Rate

All Units Conversion

Real World Energy Examples

1 kilojoule is the energy needed to heat 1 gram of water by 0.24°C

Recent Conversions

Energy Units Explained

SI Units

  • Joule (J): SI unit of energy
  • Kilojoule (kJ): 1000 joules
  • Megajoule (MJ): 1,000,000 joules
  • Gigajoule (GJ): 1,000,000,000 joules
Used worldwide in science and engineering

Nutritional Units

  • Calorie (cal): Energy to heat 1g water by 1°C
  • Kilocalorie (kcal): 1000 calories
  • Food Calorie (Cal): Actually 1 kilocalorie
  • Nutritional Joule: Used in some countries
Used for food energy content

Electrical Units

  • Watt-hour (Wh): 1 watt for 1 hour
  • Kilowatt-hour (kWh): 1000 watt-hours
  • Megawatt-hour (MWh): 1,000,000 watt-hours
  • Gigawatt-hour (GWh): 1,000,000,000 watt-hours
Used for electricity billing

Specialized Units

  • Electronvolt (eV): Used in particle physics
  • British Thermal Unit (BTU): Used in heating
  • Foot-pound (ft·lb): Used in mechanics
  • Therm: Used for natural gas
Used in specific scientific fields

About Energy Conversion

The Energy Converter helps you convert between different energy measurement units used in physics, nutrition, engineering, and everyday life. Whether you're calculating food calories, electricity bills, or scientific experiments, this tool provides accurate conversions instantly.

Common Conversion Formulas

Kilojoule to Kilocalorie

1 kJ = 0.239006 kcal
Formula: kcal = kJ × 0.239006

Kilocalorie to Kilojoule

1 kcal = 4.184 kJ
Formula: kJ = kcal × 4.184

Kilowatt-hour to Megajoule

1 kWh = 3.6 MJ
Formula: MJ = kWh × 3.6

BTU to Kilojoule

1 BTU = 1.05506 kJ
Formula: kJ = BTU × 1.05506

Practical Applications

Nutrition & Food Science

  • Food calorie calculations
  • Nutrition label conversions
  • Diet planning
  • Metabolic rate calculations

Electrical Engineering

  • Electricity bill calculations
  • Battery capacity
  • Power consumption
  • Renewable energy

Physics & Chemistry

  • Chemical reaction energy
  • Heat transfer calculations
  • Particle physics
  • Thermodynamics

Everyday Life

  • Exercise energy expenditure
  • Home heating costs
  • Appliance efficiency
  • Fuel energy content

Conversion Examples

From To Value Result Formula
2000 Kilojoules Kilocalories 2000 kJ 478.012 kcal 2000 × 0.239006
500 Kilocalories Kilojoules 500 kcal 2092 kJ 500 × 4.184
1 Kilowatt-hour Megajoules 1 kWh 3.6 MJ 1 × 3.6
100 BTU Kilojoules 100 BTU 105.506 kJ 100 × 1.05506
1 Electronvolt Joules 1 eV 1.602e-19 J 1 × 1.602e-19

How do I convert kilojoules to kilocalories?

To convert kilojoules to kilocalories, multiply the energy in kilojoules by 0.239006. For example, 100 kJ = 100 × 0.239006 = 23.9006 kcal.

What is the difference between calorie and Calorie?

A calorie (cal) is the energy needed to heat 1 gram of water by 1°C. A Calorie (with capital C) or kilocalorie (kcal) is 1000 calories - this is what's shown on food labels.

How many joules are in a kilowatt-hour?

There are 3.6 million joules (3.6 MJ) in 1 kilowatt-hour. This is because 1 watt = 1 joule/second, so 1 watt-hour = 3600 joules, and 1 kilowatt-hour = 3,600,000 joules.

What is an electronvolt used for?

An electronvolt (eV) is used in atomic and particle physics to measure very small energies, like the energy of electrons in atoms or particles in accelerators. 1 eV = 1.602×10⁻¹⁹ joules.

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