kcal to kJ – convert kilocalories to kilojoules

Convert kcal to kJ (kilocalories to kilojoules) to match food labels, gym machines and scientific energy units. This page links to the main energy converter with kcal → kJ pre-selected for you.

Open the interactive kcal → kJ converter:

Use main converter (kcal → kJ) or switch to kJ → kcal

Type any number of kilocalories (kcal) on the homepage and you’ll instantly see the result in kilojoules (kJ), with a clear equation and a shareable link.

Quick reference: kcal to kJ

The exact factor is 1 kcal = 4.184 kJ. Here are some common kilocalorie values converted to kilojoules:

Energy (kcal) Energy (kJ, approx.)
50 kcal209 kJ
100 kcal418 kJ
200 kcal837 kJ
250 kcal1,046 kJ
500 kcal2,092 kJ
1,000 kcal4,184 kJ

Why convert kilocalories to kilojoules?

People often convert kcal to kJ when they:

Related energy converters on this site

On the homepage, all energy units convert via joules (J) as a base unit. That keeps conversions consistent between kcal, kJ, J, Wh, kWh, BTU and more.