Reference table

Energy units compared

Electricity tariffs use kilowatt hours, physics uses joules, heating technology uses kilocalories or BTU. This table shows the same amount of energy in every unit of the family.

Energy units compared
Kilowatt hourJouleKilojouleWatt hourKilocalorieBTU
0.0013,600 J3.6 kJ1 Wh0.86042065 kcal3.41214163 BTU
0.0136,000 J36 kJ10 Wh8.6042065 kcal34.12141633 BTU
0.1360,000 J360 kJ100 Wh86.04206501 kcal341.21416331 BTU
13,600,000 J3,600 kJ1,000 Wh860.4206501 kcal3,412.14163313 BTU
1036,000,000 J36,000 kJ10,000 Wh8,604.20650096 kcal34,121.41633128 BTU
100360,000,000 J360,000 kJ100,000 Wh86,042.06500956 kcal341,214.16331279 BTU
1,0003,600,000,000 J3,600,000 kJ1,000,000 Wh860,420.6500956 kcal3,412,141.63312794 BTU
10,00036,000,000,000 J36,000,000 kJ10,000,000 Wh8,604,206.50095602 kcal34,121,416.33127942 BTU

Every column describes the same energy in a different unit. One kilowatt hour equals 3.6 megajoules or about 860 kilocalories. The kilocalorie is the unit used on food labels, not the calorie — 1 kcal = 1000 cal.

Sources

BIPM SI BrochureSI base units, prefixes and official SI context.NIST Guide to SI Appendix BNIST conversion-factor method and non-SI factors.

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