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Frequently Asked Questions — kcal/kg to kJ/kg

Question: How many kJ/kg is 1 kcal/kg?

Answer: 1 kcal (IT)/kg = 4.1868 kJ/kg. The International Table (IT) kilocalorie is defined as exactly 4186.8 J, so 1 kcal/kg = 4186.8 J/kg = 4.1868 kJ/kg.

Question: How do I convert kcal/kg to kJ/kg?

Answer: Multiply the value in kcal/kg by 4.1868. For example, 1000 kcal/kg × 4.1868 = 4186.8 kJ/kg = 4.1868 MJ/kg.

Question: What is the reverse conversion — kJ/kg to kcal/kg?

Answer: 1 kJ/kg = 0.2388458966 kcal/kg. Divide kJ/kg by 4.1868 (or multiply by 0.2388458966) to get kcal/kg.

Question: Where is kcal/kg used?

Answer: kcal/kg is commonly used in food science (caloric density of ingredients per kilogram), agriculture (energy content of animal feed), and traditional thermodynamics. For example, beef contains about 2,500 kcal/kg, while fat has about 9,000 kcal/kg.

Question: What is the difference between IT kcal and thermochemical kcal?

Answer: The IT kilocalorie = 4.1868 kJ (used in engineering and food). The thermochemical kilocalorie = 4.184 kJ (used in chemistry). The difference is 0.07%. This converter uses the IT calorie. For most practical purposes, the two are interchangeable.