Tensioned reinforced concrete elements are widely used in the design and implementation of reinforced concrete structures, in various conditions and investment terms, and in different environments. When these elements are used in environments that are harmful to reinforcing steel, cracks are usually prevented in the concrete in order to protect the reinforcing steel. The calculation is made on the assumption that the concrete is not cracked, and therefore it works together with the reinforcement to resist external loads. When used in environments that are not harmful to the reinforcement, cracks are allowed to form in the concrete, and the concrete is not working, and thus the reinforcement works alone. Many engineers make a mistake, believing that the bearing capacity of the element in the first case is greater than the bearing capacity of the similar element, working in the second case. The first part includes the calculation principle and the second part includes different examples of calculation, covering all possible cases of reinforced or prestressed concrete members.