Plane strain compression of cylindrical billets with flat dies has been studied in this paper. A deformation model has been proposed and the dimensions of the deformed billet cross-section for a given press stroke have been determined. To analyze the process, two types of theoretical approaches, i.e., the upper bound technique and the slab method of analysis have been applied and the required forming load has been estimated. Analytical results of billet cross-section deformed geometry and compression load have been compared with the finite element data obtained by the DEFORM 2D ver11.0 finite element package. It is shown that there is a satisfactory agreement between the theoretical predictions and the FE simulation data. The solution can be used in industrial applications for evaluating the required press load to deform the long circular cross-section billets, which is essential for selecting the forming machine with enough capacity.