Joules to kilojoules converter
Convert joules to kilojoules with an editable calculator, worked example, formula and reference table. Check the unit definitions before you convert.
Updated · How we checkUse a decimal point, such as 2.5. Enter a value in J; the result is in kJ.
Formula
Worked example
Convert 3600 J to kJ:
3600 J ≈ 3.6 kJ
Multiply your J value by the factor above. The calculator uses the full conversion factor before rounding the displayed answer.
Joules to kilojoules table
Reference values rounded to 10 significant digits. Use the converter above for other amounts.
| Joules (J) | Kilojoules (kJ) |
|---|---|
| 0.1 | ≈ 0.0001 |
| 0.5 | ≈ 0.0005 |
| 1 | ≈ 0.001 |
| 2 | ≈ 0.002 |
| 5 | ≈ 0.005 |
| 10 | ≈ 0.01 |
| 25 | ≈ 0.025 |
| 50 | ≈ 0.05 |
| 100 | ≈ 0.1 |
| 1000 | ≈ 1 |
Understanding joules
The joule measures energy or work. One watt sustained for one second transfers one joule. Joules are not a measure of power without a time interval.
Understanding kilojoules
One kilojoule equals 1,000 joules. When comparing calorie-based values, confirm the calorie definition and distinguish a small calorie from a kilocalorie.
Precision and rounding
The calculator keeps decimal precision during the conversion. Displayed values use up to 10 significant digits; an approximation sign marks the reference results. Keep extra digits until your final measurement or purchase decision.
References
Definitions and method references. Example rates and prices on this page are editable assumptions.