Joule to KilojouleConverter
Instantly convert Joule (J) to Kilojoule (kJ). Free, accurate, and easy to use.
How to Convert Joule to Kilojoule
To convert Joule (J) to Kilojoule (kJ), multiply your value by 0.001.
Example: 5 J × 0.001 = 0.005 kJ
What is a Joule?
The Joule (J) is the SI unit of energy, defined as the work done when a force of 1 Newton moves an object 1 meter. Named after 19th-century physicist James Prescott Joule, who established the mechanical equivalent of heat, it is the universal unit for all energy forms in science. Lifting a 100-gram apple one meter requires approximately 1 Joule. One food Calorie (kcal) equals 4,184 Joules.
What is a Kilojoule?
The kilojoule equals 1,000 Joules and is used on food nutrition labels in many countries — particularly in Europe, Australia, and Canada — as an alternative to calories. One kilocalorie (food Calorie) equals 4.184 kilojoules. A typical adult requires approximately 8,000–10,000 kJ of dietary energy per day. Running at moderate pace for one hour burns roughly 2,000–3,000 kJ.
Joule to Kilojoule Conversion Table
| Joule (J) | Kilojoule (kJ) |
|---|---|
| 0.001 J | 0.000001 kJ |
| 0.01 J | 0.00001 kJ |
| 0.1 J | 0.0001 kJ |
| 0.5 J | 0.0005 kJ |
| 1 J | 0.001 kJ |
| 2 J | 0.002 kJ |
| 5 J | 0.005 kJ |
| 10 J | 0.01 kJ |
| 20 J | 0.02 kJ |
| 50 J | 0.05 kJ |
| 100 J | 0.1 kJ |
| 200 J | 0.2 kJ |
| 500 J | 0.5 kJ |
| 1000 J | 1 kJ |
| 5000 J | 5 kJ |
| 10000 J | 10 kJ |
| 50000 J | 50 kJ |
| 100000 J | 100 kJ |
| 1000000 J | 1000 kJ |
| 1000000000 J | 1000000 kJ |
Frequently Asked Questions
How do I convert Joule to Kilojoule?
Multiply the Joule value by 0.001. Formula: kJ = J × 0.001. Example: 10 J = 0.01 kJ.
How many Kilojoule are in one Joule?
One Joule (J) equals 0.001 Kilojoule (kJ).
How many Joule are in one Kilojoule?
One Kilojoule (kJ) equals 1000 Joule (J).
What is the exact conversion factor from Joule to Kilojoule?
The conversion factor is 0.001. Multiply any J value by this number to get kJ. For the reverse, multiply by 1000.
How do I convert Kilojoule back to Joule?
Divide by 0.001, or equivalently multiply by 1000. Formula: J = kJ ÷ 0.001.
Is the Joule-to-Kilojoule conversion internationally standardized?
Yes. Both units are defined by international standards (SI or the international yard/pound agreement), so the conversion factor 0.001 is exact and universally agreed upon.