This article analyses the relationship between the weight and cutting edge of lithic artefacts from the main Lower Palaeolithic sites on the northern plateau (Meseta) of the Iberian Peninsula. The weight and cutting edge of a tool determine its cutting ability and the amount of force it is capable of, making them extremely important aspects of study to further our understanding of the potential capacity for human intervention in the environment. However, the analysis of these features has not received much attention in the ongoing debate on the Palaeolithic era in Europe. This study argues that the quantitative and qualitative technological analysis of these two aspects is of fundamental importance in determining the potential of lithic assemblages.