What this conversion means in practice
Kilojoules show up on packaged foods in many countries, while kilocalories (kcal) are what people still call “Calories” on US labels. Converting between them lets you compare a European kJ figure to a US diet app that expects kcal without re-deriving constants by hand.
This page uses the international steam table (IT) kilocalorie, which matches the factors in the main energy converter. If you are comparing to thermochemical data or older tables, the difference is small but not zero—always match the calorie definition your source cites.
Rough sanity check: about 4.2 kJ per kcal. If you accidentally divide instead of multiply, your meal suddenly looks ten times lighter or heavier energetically—worth a second glance before logging.
The key relationship on this page is 1 kJ = 0.238845896628 kcal. Use it for quick sanity checks: if the magnitude looks wrong, confirm you are using the same calorie or torque convention as your data source.
How to convert kilojoule to kilocalorie (it)
Multiply the kilojoule value by 0.238845896628 to get kilocalorie (it) (same factors as the full energy converter, normalized through joules).
Example: 420 kJ × 0.238845896628 = 100.31527658355 kcal
Exercise equipment that reports kilojoules burned is showing the same kind of energy as food kcal; convert with this factor to speak the same language as nutrition databases.
Kilojoule
Definition: One kilojoule is one thousand joules—a convenient SI multiple for energies larger than everyday joule counts.
History and origin: Arrived with SI prefixes to keep numbers readable as industrial and electrical systems handled larger energy flows.
Current use: Common on food labels outside the US, in exercise metrics, and in technical summaries where kJ is easier to scan than long joule strings.
Kilocalorie (IT)
Definition: The kilocalorie (IT) is one thousand IT gram-calories; it is the unit behind the word “Calorie” on most nutrition panels.
History and origin: Grew from calorimetry and steam-table work; the IT variant ties heat measurements to a specific water-heating reference.
Current use: Nutrition, dietetics, and exercise energy budgets; also appears in some industrial heat-balance discussions when kcal remains customary.
Kilojoule to Kilocalorie (IT) conversion table
| Kilojoule (kJ) | Kilocalorie (IT) (kcal) |
|---|---|
| 1 kJ | 0.238845896628 kcal |
| 4.184 kJ | 0.999331231489 kcal |
| 10 kJ | 2.388458966275 kcal |
| 100 kJ | 23.88458966275 kcal |
| 420 kJ | 100.31527658355 kcal |
| 1,000 kJ | 238.8458966275 kcal |
| 2,000 kJ | 477.691793255 kcal |
| 3,600 kJ | 859.845227859 kcal |
Kilojoule to Kilocalorie (IT) FAQ
How many kilocalories are in one kilojoule?
Using the IT definitions in this converter, 1 kJ ≈ 0.239006 kcal. Multiply kJ by that factor (or use the calculator) to get kcal.
Is a food “Calorie” the same as kcal?
Yes. On nutrition labels, “Calorie” (capital C) almost always means kilocalorie (kcal). The small calorie (cal) is one-thousandth of a kcal.
Why not use thermochemical kcal here?
The site’s energy tool standardizes on the IT pair for kJ and kcal (IT) so all pages stay consistent. For critical combustion data, confirm whether your reference uses IT or thermochemical calories.