Energy Converter
Convert joules, kilojoules, kilowatt-hours, calories, and BTU instantly. Free energy converter for physics, nutrition, and engineering work.
Last updated: September 2026
8 significant digits
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1 J = 0.001 kJ
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Common energy units
Convert energy used in electricity, heating, nutrition, and physics. Use OmniUnit for fast conversions between common units without leaving the page.
- Joule (J)
- Kilojoule (kJ)
- Megajoule (MJ)
- Watt-hour (Wh)
- Kilowatt-hour (kWh)
- Megawatt-hour (MWh)
- Thermochemical calorie (cal)
- Food Calorie (kcal)
- British thermal unit (BTU)
- US therm (therm)
- Foot-pound (ft⋅lb)
- Electronvolt (eV)