How to convert kj (kilojoules) into calories?

[Katelynnlong]

I travel a good bit to South Africa and noticed that on all their packaged goods they list kilojoules instead of calories. I want to be able to know how many calories are in the food I eat but don't know how to make the conversion. Can anyone help?

Thanks.

[convert-me.com]

I travel a good bit to South Africa and noticed that on all their packaged goods they list kilojoules instead of calories. I want to be able to know how many calories are in the food I eat but don't know how to make the conversion. Can anyone help?

Thanks.

There are 238.8 calories in 1 kilojoule. You can use Energy Converter on our site to make your conversions easily.

[Valkyrie]

Actually, the 238.8 only applies to energy. In food it is 1 calorie to 4.186 kJ. So a lunch bar with 1028 kJ will be 245.58 calories which for some of us translates to 30 minutes on the treadmill. :lol:

[Snitray]

There are 238.8 calories per kilojoule.

So if your lunch bar is 238.8 kilocalories (which is actually 238,800 calories), then that means it is 1000 kilojoules.

A lunch bar 238.8 calories would be the size of an ant. It is more likely that you are thinking of kilocalories. A typical meal will be around 600 kilocalories.

[Guest]

Being in Australia, we often get people referring to Americanisms, such as the Imperial archaeic system (e.g, their way of measuring energy, ergo - "calories"), which of course makes no logical sense.

I will have you know that there are exactly 4.186 kilojoules for every calorie.
I have a dieticitan, and I am told that I have a daily energy requirement of 9580 kj, and for those who are innumerate (or perhaps just illiterate and have not read the above) that translates to exactly 2288.58 calories.

What you other people are referring to is charged energy, such as light, heat etc. Check what you are about to quote before you post it please - that way there will be no confusions.

And a lunch bar with 1000 kj is about normal. It is physically impossible for it to be the "size of an ant."

[Guest]

Being in Australia, we often get people referring to Americanisms, such as the Imperial archaeic system (e.g, their way of measuring energy, ergo - "calories"), which of course makes no logical sense.

I will have you know that there are exactly 4.186 kilojoules for every calorie.

Well, if it were really Imperial, it would be in British Thermal Units (BTU). The calorie is actually an obsolete unit of the metric system that is not used in the modern SI.

Actually, there are two problems here:
*There is a calorie and a Calorie (also called kilogram calorie). The food calorie is a "large C" Calorie, it is the energy to heat 1 kg of water 1 degree C. Some of the conversion factors given above are for gram calories

*Water sucks as a standard because the energy required to heat a gram or kilogram 1 degree ALSO depends on the starting temperature, it is not constant. There are several "flavors" of calorie including IT (International Steam Table, the thermo ("th"), the mean, the 15 °C, and the 20 °C (gram) calorie, ranging from 4.1819 to 4.19002 J/cal. At least three of these are used (x1000) for nutritional kilocalories (the kilo usually isn't mentioned). These values for "IT", "th", and "mean" are 4186.8, 4184, and 4190.02 joules, respectively, so take your pick. Probably, the thermo-chemical makes the most sense (4184 J or 4.184 kJ) as that is what the metabolic process is. (All figures from NIST SP811)

[Guest]

Thank you for finally making the distinction between calories and Calories (what nearly everyone wanted to be refering to). I was getting sick of reading through all of these people who were simply confusing themselves because they were using the wrong term.