Abstract This paper deals with the calculation of decrease of hypothetical melting point of g-Fe due to the admixed elements according to the Le Chatelier-Šreder equation. Two cases are considered in the calculations: a) equilibrium of pure g-iron with ideal melt of admixture containing iron b) ideal solid solution of austenite with ideal melt of admixture containing iron Hypothetical melting point of g-iron was calculated from melting enthalpy and entropy of d-iron taking into account the enthalpy and entropy of allotropic transformation of g-iron to d-iron. Theoretical decrease of the hypothetical g-iron melting point for binary systems (wi=1%) are shown in the form of periodic table. Decrease of hypothetical melting point of g-iron for multi-component system (Hadfield austenite manganese steel) is calculated as the sum of hypothetical melting point decrease of the individual binary systems assuming no or negligible interaction between admixed elements. While the decrease of hypothetical melting point calculated for case a) is typically too high due to the unrealistic equilibrium of pure g-iron with ideal melt, the calculated value for case b), i.e. ideal solid solution of austenite with ideal melt, is in reasonable agreement with the experimental data for similar composition of austenite.