In this paper the flexural strength analysis of reinforced and prestressed concrete members with symmetrical cross‐sections loaded in the plane of symmetry is performed. A new practical method for determining the height of the compression zone is proposed. The method is valid for normal and high‐strength concretes and for different distributions of bars along the section. It is based on the assumptions, simplifications and material properties of Eurocode 2. Design equations have been developed for the rectangular stress distribution in the concrete compression zone and for the steel stress‐strain diagrams with a horizontal and inclined top branch. A numerical example is presented to show the method usage.