In order to be accurate for the reliability of real‐time heat transfer model for online control of continuous casting process of steel and also to be easily embeddable, special algorithms have been developed for calculation of solidification‐related thermophysical properties of carbon and low alloy steels. These thermophysical properties include density, thermal conductivity, and enthalpy‐related data, i.e., enthalpy and specific heat. In the algorithms, Fe‐C pseudobinary phase diagram, which is similar to Fe‐C phase diagram but is influenced by contents of steel alloying elements other than carbon, has been introduced as the basis to solve the phase fractions of steel as functions of temperature. Associated with the solved phase fractions, the thermophysical properties can be calculated from 1600 to 0 °C by combining corresponding data of different phases, which are fitted as polynomial functions of temperature and steel composition. Finally, the algorithms have been tested as the calculated results showed good agreement with the calculated data by software JMatPro and also the measured data.