Kilojoule to Joule Converter
Convert kilojoules to joules instantly with an energy calculator built for science, nutrition, HVAC, electricity, engineering, and everyday reference.
kJ to J Calculator
Enter an energy value and the conversion updates automatically.
Result updates automatically.
Formula: joules = kilojoules × 1000
How to Convert Kilojoule to Joule
Energy conversion uses joules as the SI reference unit. Multiply the source energy by the factor shown below to convert it into the selected output unit.
1 kilojoule
1000 joules
10 kilojoules
10000 joules
100 kilojoules
1e+5 joules
Energy Formula Notes
The calculator converts through joules as the base energy unit, then formats the result for the selected energy unit.
kJ to Joules Converter FAQ
Which energy units are supported?
This tool supports joules, kilojoules, BTU, small calories, kilocalories, watt-hours, kilowatt-hours, foot-pounds, and newton-meters.
How do I convert kJ to J?
Multiply the kJ value by 1000 to get J. The calculator performs the formula automatically.
Can I reverse the energy conversion?
Yes. Use the swap button to reverse the selected units and calculate the opposite direction.