Abstract The article presents approach for optimization of cutting parameters for minimizing direct energy consumption during turning. Presented are the results of the experimental studies of the dependence of the specific energy consumption by material removal rate (MRR) when turning of steel using CNC lathes and an improved empirical model of this dependence. This model is used for the formulation of a model of direct energy consumption expressed by the cutting parameters. An equation for the optimal cutting speed is devised by applying the minimum energy criterion. The influences of the insert grade, of the feed and depth of cut on the minimum energy consumption have been found through numerical research. Recommendations for their selection have been made based on considerations for minimum energy during turning.