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Kilocalories to Kilojoules Converter

Convert kilocalorie to kilojoule instantly. Type a value below — the result updates as you type.

When you need to convert kilocalorie to kilojoule

Energy conversions appear on nutrition labels, utility bills and appliance specs, letting you compare food energy, electricity use and heating output on a common scale.

Nutrition labels show energy in both kilojoules and kilocalories (Calories), so converting compares foods directly.

Typical values: 0.5 kcal is about 2.092 kJ, and 100 kcal works out to roughly 418.4 kJ. Because the ratio is fixed at 4.184, you can scale any amount linearly — doubling the kilocalories doubles the kilojoules.

Food packaging, power meters and heating equipment each prefer different energy units, so converting makes them directly comparable.

How to convert kilocalorie to kilojoule

One kilocalorie equals 4.184 kilojoules. To convert, multiply the number of kilocalories by 4.184:

kilojoules = kilocalories × 4.184

For example, 10 kilocalories × 4.184 = 41.84 kilojoules.

Kilocalories to kilojoules conversion table

Energy (kcal)Kilojoules (kJ)
1 kcal4.184 kJ
2 kcal8.368 kJ
3 kcal12.552 kJ
5 kcal20.92 kJ
10 kcal41.84 kJ
20 kcal83.68 kJ
50 kcal209.2 kJ
100 kcal418.4 kJ

FAQ

How many kilojoules are in a kilocalorie?

One kilocalorie = 4.184 kilojoules.

How do I convert kilojoules back to kilocalories?

Divide by 4.184, or use the kilojoules to kilocalories converter.

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