calorific value

noun2

1. •
   The amount of energy produced by the complete combustion of a material or fuel. Measured in units of energy per amount of material, e.g. kJ/kg.

   • The engine was fired with Welsh (Bedwas) coal having a calorific value of 13,800 B.T.U. per lb. as received, and 13,970 B.T.U. per lb. in the dry condition. — 1960
2. •
   The amount of energy available from an item of food when digested, mostly from carbohydrates and fats