This European Standard establishes an evaluation procedure for determining equivalent conicity. A benchmark calculation is specified to achieve comparable results on a consistent basis for the equivalent conicity, which may be calculated by different methods not given in this European Standard. This European Standard also proposes possible calculation methods. Informative examples of the use of the Klingel formula (see Annex B) and linear regression of the (delta)r-function (see Annex C) are included in this European Standard. This European Standard includes reference profiles, profile combinations, tolerances and reference results with tolerance limits, which allow the user to assess the acceptability of a measuring and calculation system including random- and grid- errors of the measuring system. It sets down the principles of calculation that need to be followed but does not impose any particular numerical calculation method. This European Standard does not define limits for the equivalent conicity and gives no tolerances for the rail profile and the wheel profile to achieve acceptable results for the conicity. For purposes outside the scope of this European Standard (e.g. simulation of vehicle behaviour) it can be useful or necessary to use more sophisticated theories. These methods are not within the scope of this European Standard. For the application of this European Standard some general recommendations are given in Annex I.