Why a white paper for DEM calibration? Although DEM simulations are increasingly used in many research and industrial fields, a standard approach for the determination of the right contact model parameters does not currently exist. The white paper is aimed to provide an overview about best practices for DEM simulation in the field of bulk material handling. The style of the paper is focussed on a comprehensive overview, not about a discussion or description of certain details. However, such a detailed description is required for the full understanding of the content. Hence, this white paper contains a number of important references. The white paper is planned as a ongoing project which can be changed and extended regarding the content and authors. The paper makes no claim to completeness but summarises the knowledge and experience of many experts to give an holistic overview of the topic.