Energy / kJ → J
Convert Kilojoules to Joules
Convert work, heat, and stored energy using joules as the base. Convert Kilojoules (kJ) to Joules (J). Find the formula, worked examples, unit definitions, and practical guidance below.
Reverse: Joules to Kilojoules →
How to convert kilojoules to joules
Calories use the thermochemical definition. Btu use the International Table definition. Food Calories are kilocalories, not single calories.
Use x for the value in kJ, b for the intermediate value in J, and y for the result in J.
J = kJ × 1000
Worked examples
10 kJ ≈ 10000 J
Step 1: (10 × 1000) ≈ 10000 J.
Step 2: 10000 ÷ 1 ≈ 10000 J.20 kJ ≈ 20000 J
Step 1: (20 × 1000) ≈ 20000 J.
Step 2: 20000 ÷ 1 ≈ 20000 J.
Results are rounded to 12 significant digits. Converting units does not increase the precision of the original measurement. Very large or small values outside JavaScript’s finite numeric range are rejected.
About Kilojoules
Kilojoules (kJ) measures energy under the conventions above. The base value in J is (x × 1000), where x is the numerical value in kJ. Factors shown here are rounded for display; calculations use the stored factor.
About Joules
Joules (J) measures energy under the conventions above. The base value in J is (x × 1), where x is the numerical value in J. Factors shown here are rounded for display; calculations use the stored factor.
Definitions and sources
Carry the same physical assumptions into subsequent physics calculations.
Kilojoules to joules reference table
| Kilojoules (kJ) | Joules (J) |
|---|---|
| 1 | 1000 |
| 5 | 5000 |
| 10 | 10000 |
| 25 | 25000 |
| 50 | 50000 |
| 100 | 100000 |
| 1000 | 1000000 |
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