Kilojoule (kJ)
The kilojoule (kJ) is 1000 joules. Food labels in Australia, New Zealand and the EU give energy in kJ alongside kcal.
Symbol: kJ
Quantity: energy, work and heat
SI relation: 1 kJ = 1000 J (exact)
Derivation: 1 kJ = 10³ J
Exact: yes, by definition
Typical uses
- Nutrition labels (kJ per serving)
- Heats of reaction (kJ/mol)
- Steam tables and enthalpy (kJ/kg)
Convert kilojoules to other units
| Conversion | 1 kJ equals | Reverse |
|---|---|---|
| kilojoule to joule | 1000 J | joule to kilojoule |
| kilojoule to kilocalorie | 0.2390057361 kcal | kilocalorie to kilojoule |
| kilojoule to kilowatt-hour | 0.0002777777778 kWh | kilowatt-hour to kilojoule |
| kilojoule to BTU | 0.9478171203 BTU | BTU to kilojoule |
| kilojoule to megajoule | 0.001 MJ | megajoule to kilojoule |
| kilojoule to calorie | 239.0057361 cal | calorie to kilojoule |
| kilojoule to watt-hour | 0.2777777778 Wh | watt-hour to kilojoule |
| kilojoule to therm | 0.00000948043428 thm | therm to kilojoule |
| kilojoule to electronvolt | 6.241509074 × 10²¹ eV | electronvolt to kilojoule |
| kilojoule to foot-pound | 737.5621493 ft·lbf | foot-pound to kilojoule |
| kilojoule to erg | 10000000000 erg | erg to kilojoule |
Open the Energy Converter to convert any value between all units.
Sources
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 7, SI prefixes.
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Kilojoule (kJ). Retrieved October 17, 2026, from https://scientificconverters.com/units/kilojoule/
IEEE
Scientific Converters, "Kilojoule (kJ)," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/units/kilojoule/