Discussions at the European Commission, in academic journals as well as at conferences for academics and practitioners, indicate that there is a lack of clarity how to coincide anticompetitive sustainability agreements with the so-called economic approach of the European Commission. The current interpretation of the economic approach, most notably the European Commission guidelines issued in 2004 on the application of Article 101(3) of the Treaty on the Functioning of the European Union (TFEU), has led to situations where agreements between undertakings to stop the sale of unsustainable products or production processes have been discouraged. In this article, it is examined how the current European Commission guidelines could be improved to allow undertakings to assess their agreements in a way that is quantifiable but that goes beyond an economic approach focusing solely on monetary well-being. This article gives a legal overview of Article 101 TFEU and the guidelines, followed by an exploration of different methods to quantify agreements under Article 101(3) TFEU.