The topic of this thesis is a parametric analysis of the resistance of laterally supported steel beams exposed to axial force and bending moment. The analysis was carried out on series of rolled IPE, HEA and HEB profiles, varying all the steel classes defined in the current and future standards for the design of steel structures. In the first part of the thesis, a theoretical introduction to the European norms for design of steel structures (HRN EN 1993-1-1: 2014 and FprEN1993-1-1: 2022) is given. The differences in mentioned norms for design of steel structures were considered, with an emphasis on the procedure for determining the resistance of laterally supported steel beams. The classification of cross-sections is described in more detail, because the greatest differences in the considered norms were observed regarding classification of cross-sections. In order to understand the comprehensive impact of the new classification limits,, an example of design of laterally supported steel beams according to the current and future norm is presented in detail. Finally, as a result of the parametric analysis, the tables with the classification results and ultimate utilization depending on the loading type, steel class and profile type are presented. The differences were highlighted and the conclusions about the benefits of the changes brought by the second generation of standards for design of steel structures were drawn out.