kJ to J Converter - Kilojoule to Joule

Kilojoule (kJ) to Joule (J)

Direct answer

1 kJ = 1,000 J

J = kJ × 1,000

Converter

Input

Result

1,000J

J = kJ × 1,000

kJ = J × 0.001

Example: 10 kJ = 10 × 1,000 = 10,000 J.

Express both kJ and J in the same base unit J (joule), then cancel the shared base unit.

1
Rewrite kJ in the base unit
$1 kJ = 1, 000 J$
2
Rewrite J in the base unit
$1 J = 1 J$
3
Forward conversion
$1 kJ = \frac{1 , 000 J}{1 J} \times 1 J = \frac{1 , 000}{1} J = 1, 000 J$
4
Reverse conversion
$1 J = \frac{1 J}{1 , 000 J} \times 1 kJ = \frac{1}{1 , 000} kJ = 0.001 kJ$

A guarded explanation for this pair page covering definition, principle, assumptions, and cautions.

Guarded output

AI text is for interpretation only. The page calculator remains the source of truth for numeric results.

1 kJ = 1,000 J.

10 kJ = 10,000 J.

100 kJ = 100,000 J.

Use J = kJ × 1,000.

1 J = 0.001 kJ.

Use the conversion factor and round the result to the precision required by your calculation.