Kilojoules to Joules converter

To convert kilojoules to joules, enter the value in the first field. The result in joules is calculated automatically using the exact conversion factor.

1 kJ = 1000 J
1 J = 0.001 kJ

Formula: J = kJ × 1000
kJ = J × 0.001

Definitions: 1 kJ = 1000 J

The kilojoule (kJ) is 1,000 joules. It is used for food energy on nutrition labels in Australia, New Zealand and Europe, often next to kcal, and for reaction energies in chemistry.

The joule (J) is the SI unit of energy and work: the energy of one newton acting over one meter, or of one watt working for one second. It is a small unit, roughly the energy needed to lift a small apple by one meter.

See the conversion table with commonly used values, handy for quick reference or study.