A technique for calculating the parameters of the shape of the boundary and areas of contact indentations of a pipe billet with a roller tool of a forming mill, in which the boundaries of the shape of the contact indentation are described by rectilinear lines, and the shape is modeled by triangles on the plane of the pipe billet, is investigated. The results of an experiment on fixing the contact sections of a tubular billet with initial dimensions of 160×1.5×1800 mm from steel 09G2S with rolls in the section of open pass are presented. As a result of the experiment, the contact areas of the pipe billet with the lower and upper rolls were fixed. The boundary of the experimental contact areas are curved arcs. Comparison of the experimental data with the technique showed that the parameters of the boundaries of the contact area according to the technique lead to an overestimation of the values by 30-40 % compared to the experimental data. On the basis of experimental data, the development of the existing technique for determining contact areas is presented, in which the boundaries are defined in the form of arcuate curves. The boundaries of the entry contact sections for the lower and upper rolls are determined by the equations of exponential approximation. Taking into account the equations of the boundaries of the sections, a method is presented for determining the areas of contact sections of a pipe billet on the surfaces of the lower and upper rolls, the results of which do not exceed 6 % of the experimental data. The engineering mathematical software PTC Mathcad Prime 6.0 was used to calculate and construct the areas of contact areas.