A method for determining a shape of a mistuned blade of an impeller includes: providing a nominal blade with radially threaded-on profile elements; providing an initially mistuned blade with profile elements, the mistuned blade having a reduced or increased thickness at at least one of the profile elements compared with the nominal blade; determining the shape of the nominal blade in a hot state; determining the shape of the mistuned blade in the hot state; comparing the two shapes and determining a parameter of the mistuned blade which differs from the corresponding parameter for the nominal blade in the hot state; and changing the value of this parameter for the mistuned blade in the cold state such that the difference between the parameter for the mistuned blade and the nominal blade in the hot state no longer exists.