kilojoule

unit of energy measurement

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July 16, 2026

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A kilojoule (kJ) is a unit of energy measurement, equivalent to 1,000 joules. The joule, named after physicist James Prescott Joule, is the standard unit of work or energy in the International System of Units (SI). It represents the work done when a force of one newton acts over a distance of one meter. In electrical terms, one joule is equal to one watt-second.123

In nutrition, kilojoules are also used to measure the energy value of foods, with 1 kilocalorie being equal to 4.184 kilojoules.4

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calorie
…has been proposed that the kilojoule replace the kilocalorie as the unit of choice for discussing the energy value of foods. Such a change would bring the nomenclature of food scientists into closer agreement with that of other scientists. The conversion factor for expressing kilocalories as kilojoules, as recommended by…
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…has been proposed that the kilojoule replace the kilocalorie as the unit of choice for discussing the energy value of foods. Such a change would bring the nomenclature of food scientists into closer agreement with that of other scientists. The conversion factor for expressing kilocalories as kilojoules, as recommended by…
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human nutrition
Calories and kilocalories: energy supply
…likely to be measured in kilojoules (1 kilojoule = 10³ joules) or megajoules (1 megajoule = 10⁶ joules). One kilocalorie is equivalent to 4.184 kilojoules.
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…likely to be measured in kilojoules (1 kilojoule = 10³ joules) or megajoules (1 megajoule = 10⁶ joules). One kilocalorie is equivalent to 4.184 kilojoules.
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