⚡ Energy
kcal to kJ Converter
Convert kcal to kJ instantly with a reference conversion table.
Quick answer: To convert kcal to kJ, multiply by 4.184. For example, 1 kcal = 4.184 kJ. Use the calculator below for any value.
kcal to kJ
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Common conversions
| kcal | kJ |
|---|
Formula:
How to convert kcal to kJ
1
Enter your value
Type the number of kcal you want to convert into the left box. The result in kj appears instantly in the right box. You can also type into the right box to convert in the other direction.
2
Use the swap button
Click the ⇄ Swap button to reverse the conversion — kJ to kcal. Your current value carries across so you don't have to re-enter anything.
3
About kcal and kJ
kcal and kJ are common energy measurements.
💡 Did you know?
1 kcal = 4.184 kJ exactly. EU food labels show both; UK labels often only kcal. The 'Calories' on a US food label (capital C) = kcal — but UK and EU lower-case 'calories' technically means small calories. Confusing!
📊 Common conversions at a glance
| kcal | kJ |
|---|---|
| 1 | 4.184 |
| 2 | 8.368 |
| 5 | 20.92 |
| 10 | 41.84 |
| 50 | 209.2 |
| 100 | 418.4 |
Reviewed for 2026. kcal ↔ kJ conversion factor verified against published reference data. Built by a UK-based qualified primary teacher and FA Level 2 coach as part of 247QuickTools' free utility-tools project.