Energy conversion

Convert Joule to Kilojoule

1 joule (J) equals 0.001 kilojoule (kJ). Enter any value below to convert from J to kJ.

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1 J = 0.001 kJ

All Energy units

From 1 J
UnitValue
Joule J 1
Kilojoule kJ 0.001
Thermochemical calorie cal 0.2390057361
Kilocalorie kcal 0.0002390057
Watt-hour Wh 0.0002777778
Kilowatt-hour kWh 0.0000002778
BTU (International Table) BTUₕᵀ 0.0009478171
Foot-pound ft·lb 0.7375621493
Electronvolt eV 6.2415090745e18
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Formula

J to kJ conversion formula

Use this relationship for a direct conversion:

kJ = J x 0.001

Worked example

2 J = 0.002 kJ.

The thermochemical calorie and International Table BTU are named explicitly to avoid ambiguous legacy definitions.

Quick reference

Joule to Kilojoule table

Joule (J)Kilojoule (kJ)
0.010.00001
0.10.0001
10.001
20.002
50.005
100.01
250.025
500.05
1000.1
1,0001

From unit

About the joule

The SI unit of energy, equal to one newton meter.

Symbol: J

To unit

About the kilojoule

One thousand joules.

Symbol: kJ

Keep converting

Related conversions

Kilojoule to JouleReverse this conversion Joule to Thermochemical calorieJ to calJoule to KilocalorieJ to kcalJoule to Watt-hourJ to WhJoule to Kilowatt-hourJ to kWhJoule to BTU (International Table)J to BTUₕᵀJoule to Foot-poundJ to ft·lb

Source

Conversion standard

Definitions are checked against NIST SP 811: Energy units. Calculations use full internal precision before display rounding.

View the complete energy converter

Questions

J to kJ FAQ

How do you convert joule to kilojoule?

Use the formula kJ = J x 0.001. 1 joule (J) equals 0.001 kilojoule (kJ).

Is the J to kJ conversion exact?

Both unit definitions use exact factors. Only the displayed decimal may be rounded.