High pressure torsion (HPT) is a severe plastic deformation (SPD) method that can transform the characteristic lamellar microstructure of pearlitic steel to a severely deformed and aligned microstructure with respect to the deformation direction. In the current paper, HPT experiment results for the standard rail grade R260 were utilised to calibrate a material model formulated for large deformations to predict evolution of anisotropy due to microstructural changes in pearlitic steel. The HPT deformation procedure is simulated in the commercial Finite Element (FE) package ABAQUS. Numerical results agree well with experimental data demonstrating the high potential of the proposed material model in analyses including large deformations of pearlitic steel, e.g. in railway applications and Rolling Contact Fatigue (RCF) analyses.