The first step of any EU merger control analysis is to assess whether or not a transaction falls within the jurisdiction of the EU Merger Regulation, which only applies to concentrations with an 'EU dimension’. To assess whether there is an EU dimension, it is necessary to consider the turnover (or revenue) of the parties to a transaction, and there are specific rules relevant to the calculation of turnover. This Practice Note looks at how turnover is calculated, with reference to the EU Merger Regulation (Regulation 139/2004) and the European Commission’s Consolidated Jurisdictional Notice.