This thesis analyses and compares several methods, known from the professional literature, that enable the conversion of pump operating characteristics into operating characteristics these machines would have if they were operating in turbine regime. The results of the calculation of turbine operating characteristics for one single-stage and one split-case pump are compared with the available, actually measured turbine characteristics of these two pumps. The introductory part of the thesis presents the theoretical background of the operation of pumps and turbines and explains in detail the selected methods for conversion of pump performance character-ristics into turbine characteristics.