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Energy Converter

Joules, calories, kilowatt-hours, BTU

From unit
Joule
To unit
Kilojoule

Supported energy units

This converter supports 9 units. Each conversion is calculated using the standard SI definition where applicable.

  • Joule (J)
  • Kilojoule (kJ)
  • Calorie (cal)
  • Kilocalorie (kcal)
  • Watt-hour (Wh)
  • Kilowatt-hour (kWh)
  • BTU (BTU)
  • Electron Volt (eV)
  • Foot-pound (ft·lb)

Popular energy conversions

Quick reference for the most-searched energy conversions.

  • 1 kcal to kJ = 4.184 kJ
  • 1 kWh to J = 3600000 J
  • 1 BTU to J = 1055.06 J
  • 1 cal to J = 4.184 J

Energy converter FAQ

How many kilojoules are in 1 kilocalorie?
1 kilocalorie (kcal) equals 4.184 kilojoules (kJ).
How many joules are in 1 kilowatt-hour?
1 kilowatt-hour (kWh) equals 3600000 joules (J).
How many joules are in 1 btu?
1 btu (BTU) equals 1055.06 joules (J).
How many joules are in 1 calorie?
1 calorie (cal) equals 4.184 joules (J).
What is a energy converter?
A energy converter instantly translates a value from one energy unit to another. Unit Guru supports 9 energy units, with the Joule (J) as the SI base unit.
How accurate is the energy conversion?
Every conversion uses the standard SI definition or the official conversion factor. Results are computed in your browser using double-precision arithmetic, so they're as accurate as the source units allow.
Is the energy converter free?
Yes — Unit Guru is 100% free with no ads, no signup, and no tracking. All conversions run client-side in your browser.

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