Kcal to KJ converter

How to convert kilocalories to kilojoules

To convert kilocalories to kilojoules, use kJ = kcal × 4.184. For example, 2,000 kcal is 8,368 kJ. Type any value in the converter above and the result updates instantly.

The Kcal to KJ formula

The conversion is kJ = kcal × 4.184. One kilocalorie equals 4.184 kJ. This conversion is exact: kilocalorie is defined precisely in terms of kilojoule, so the only rounding is in the digits shown.

Kcal to KJ conversion table

Where kilocalories and kilojoules are used

Kilocalories are the 'calories' printed on food labels in most countries.

Kilojoules are the SI energy unit and appear on food labels in Australia, New Zealand and Europe.

Worked examples

These examples use the formula above, so you can check the converter or do the same by hand:

• 100 kcal = 418.4 kJ
• 500 kcal = 2,092 kJ
• 1,500 kcal = 6,276 kJ

Converting kilocalories to kilojoules in your head

Multiply by 4: 500 kcal is about 2,000 kJ (exactly 2,092 kJ).

KJ to Kcal reference table

For the opposite direction, these values are handy to have at hand:

Common mistakes to avoid

• The 'calories' on food labels are kilocalories (kcal), not small calories (cal).
• One kilocalorie is 4.184 kilojoules; labels that show both may round slightly differently.

About this converter

The converter accepts whole numbers, decimals and negative values, gives the result as you type, and uses full precision internally, so what you copy is as accurate as it can be. It runs in your browser: nothing you type is sent to a server, it keeps working offline once the page has loaded, and there is nothing to install.

Need the opposite direction? Use the KJ to Kcal converter.