Energy

The coherent SI unit of energy is the joule, J.

Factors in boldface are exact

Convert From To Multiply Std
kilojoules kJ J 1000 3
megajoules MJ J 1.0 x 106 3
gigajoules GJ J 1.0 x 109 3
terajoules TJ J 1.0 x 1012 3
watt hour W.h J 3600 1
kilowatt hour kW.h J 3.6 x 106 3
watt second W.s J 1 1
British thermal unit BtuIT J 1.055056 x 103 2
kilo British thermal unit kBtuIT J 1.055056 x 106 3
million British thermal unit MMBtuIT J 1.055056 x 109 3
decatherm dT J 1.055056 x 109 3
calorie calIT J 4.1868 2
kilocalorie kcalIT J 4186.8 3
million kilocalorie MMkcalIT J 4.1868 x 109 3
decatherm dT J 1.055056 x 109 3

1: BS 350:2004 Table 37

2: BS 350:2004 Table 38

3: BS 350:2004 Section 37

Note on the calorie: The Fifth International Conference on the Properties of Steam (London, July 1956) defined the International Table calorie as 4.1868 J. Therefore the exact conversion factor for the International Table Btu is 1.055 055 852 62 kJ. Note that the notation for International Table used in this listing is subscript ‘‘IT’’. Similarly, the notation for thermochemical is subscript ‘‘th.’’ Further, the thermochemical Btu, Btuth, is based on the thermochemical calorie, calth, where calth = 4.184 J exactly.

 

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