Both kilojoules (kJ) and calories (cal) are units of energy generally used in the context of nutrition. Converting kilojoules into calories (or vice versa) is very simple and allows you to know the energy value of different foods.
Steps
Method 1 of 2: Converting Kilojoules to Calories
Step 1. Start with the number of kilojoules (kJ)
Energy is often measured in kilojoules (kJ), but you can convert it to calories (cal) in a few simple steps.
For example, let's say you want to convert 5 kJ into calories
Step 2. Multiply the kilojoules (kJ) by 1,000 to get the number of joules (J)
Note that 1 kilojoule equals 1,000 joules. To convert kilojoules to joules, you then need to multiply their value by 1,000.
In our example, you will need to multiply 5 kJ by 1,000 and you will get the following result: 5,000 J
Step 3. Multiply the number of joules by 0, 239 to get the number of calories
Note that 1 joule equals 0.23 calories (1 J = 0.23 cal), so to perform the joule to calorie conversion all you need to do is multiply its value by 0.239.
For example, multiply 5,000 J by 0, 239 and you get the following value: 1,195 cal. This means that 5 kilojoules equals 1,195 calories (5 kJ = 1,195 cal)
Step 4. Convert calories (cal) to kilocalories (kcal) if desired
Just divide the number of calories by 1,000 to get the same value in kilocalories.
In our example, you will need to divide 1,195 cal by 1,000 and you will get the following result: 1,195 kilocalories. This means that 5 kilojoules equals 1, 195 kilocalories (5kJ = 1, 195 kcal)
Method 2 of 2: Converting Calories to Kilojoules
Step 1. Divide the number of calories (cal) by 1,000 to get the same value in kilocalories (kcal)
If you haven't already, convert the number of calories to kilocalories.
For example, if you have 25 calories, divide the number by 1,000 and you will get the following result: 0, 025 kcal
Step 2. Multiply the kilocalories (kcal) by 4,185 to find the number of kilojoules (kJ)
Note that 1 kcal = 4, 184 kJ. Therefore, to convert kilocalories to kilojoules you need to multiply their value by 4, 185.
For example, multiplying 0, 025 kcal by 4, 184 will give you the following result 0, 105 kJ. This means that 25 calories equals 0, 105 kilojoules
Step 3. Convert kilojoules (kJ) to joules (J) if desired
If you need to know the number of joules instead of kilojoules, just multiply it by 1,000.
