calories, kilocalories, calories and kilojoules are all units of heat. One calorie is the heat needed to raise the temperature of 1 gram of water by 1 degree Celsius after the food we eat is burned, and one kilocalorie is the heat needed to raise the temperature of 1 liter of water by 1 degree Celsius, which is also called a kilocalorie. \ r \ nCalory (abbreviated as "calorie" or "calorie") is defined as the heat required to raise 1 gram of water to 1 degree Celsius at 1 atmosphere. 1 kilocalorie is equal to 1 calories, about 4184 joules. The calories of fat are about 9 kilocalories per 1 grams; Sugar and protein have only 4 calories per 1 grams. \r\nThe conversion between them is: \ r \ n kcal = kcal \r\n1 kcal =1 kcal \r\n1 kcal =1 joules \r\n1 kcal /1 kcal =1 kcal \r\n1 kcal /1 kcal =4.184 kcal.