Unit Converter - Energy

Energy units

The energy converter allows quick conversion between energy and work units — from joules and kilowatt-hours, through calories and BTU, to tonnes of oil equivalent. An essential tool for thermal, electrical, and energy source comparison calculations.

Overview of energy units

• Joule [J]: the basic unit of energy in the SI system. It corresponds to the work done by a force of one newton moving an object 1 meter in the direction of the force.
• Megajoule [MJ]: one million joules. 1 MJ is 1000 kJ or 1,000,000 J.
• Calorie [cal]: a unit of thermal energy equal to the amount of heat needed to raise the temperature of 1 g of water by 1 °C at atmospheric pressure. One calorie is about 4.184 J.
• Kilocalorie [kcal]: one thousand calories, or 1000 cal. A unit often used to express the energy value of food or the body's energy requirements. One kilocalorie is about 4.184 kJ.
• Watt-hour [Wh]: a unit of electrical energy equal to the amount of energy used by a device with a power of 1 W operating for one hour. One watt-hour is 3600 J.
• Kilowatt-hour [kWh]: one thousand watt-hours, or 1000 Wh. A unit often used to express household or business electricity consumption. One kilowatt-hour is 3.6 MJ.
• Megawatt-hour [MWh]: one million watt-hours, or 1,000,000 Wh. A unit often used to express large-scale electricity production or delivery. One megawatt-hour is 3.6 GJ.
• British thermal unit (BTU): a unit of thermal energy equal to the amount of heat needed to raise the temperature of a pound (about 454 g) of water by one degree Fahrenheit. One BTU is about 1055 J.
• Therm: a unit of thermal energy equal to one hundred thousand British thermal units (BTU), or about 105,506,000 J. A unit often used to express natural gas consumption.
• Tonne of oil equivalent [toe]: a unit of primary energy equal to the amount of energy obtained from burning one tonne of crude oil with an average calorific value of about 41,868,000 kJ (10 MWh). A unit often used to compare different energy sources and forms.

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