It can be defined as the amount of heat liberated in KJ or Kcal by the complete combustion of 1 Kg of fuel.

There are two types of calorific values

Higher calorific value (HCV) = It is the total heat liberated in KJ or Kcal by the complete combustion of 1 Kg of fuel.

Lower calorific value (LCV) = It is the difference of Higher calorific value and heat absorbed by water vapors.

LCV = (HCV – x.588.76) Kcal/Kg

Where ‘x’ is the fraction of water vapors.