Calorie is a common term in the coal industry. 1 kg coal, calorific value 1000 kcal, equivalent to 0. 143 kg standard coal; It is also a unit of heat, equivalent to an engineering unit of kilocalories, and is mostly used for nutrition measurement and fitness manuals.

Calories, or simply calories, are defined as the heat required to raise 1 gram of water to 1 degree Celsius at 1 atmospheric pressure. Modern science no longer uses "calorie" as the unit of measurement of heat and energy, but adopts the international unit Joule.