Although Joule is the unit of energy we normally use in science, people also use the Kilocalorie and the gram calorie when describing energy; especially where food energy is concerned. These are potentially confusing because 1 kilocalorie does not equal 1 gram calorie. Here's how it works:
• It takes 4.184 J to heat one gram of water 1 K
• It takes one gram calorie to heat one gram of water 1 K
• This means that 1 gram calorie = 4184
• 1 kilocaloric equals 1000 gram calories
• This means that 1 kilocalorie - 4184
The kilocalorie is also called the Dietary Calorie or Food Calorie. Convert your results to kilocalories per gram.

One kilocalorie is equals to 1000 gram calories because one kilo is equals to or have 1000 grams. One kilocalorie is equals to 4184 Joules of energy while on the other hand, one calorie is equals to 4.184 Joules of energy because one calorie is 1000 times smaller than Kilocalorie so calorie has also 1000 times lower energy than kilocalorie. Kilo is the prefix which means 1000 so we can say that One kilocalorie is equals to 1000 gram calories.