The paper provides an overview of the different approaches to measure returns-to-scale (RTS) in Data Envelopment Analysis (DEA). DEA is a promising approach allowing for analysis of efficiency and RTS in certain fields where other concepts like regression analysis are not applicable. Therefore, DEA literature and especially literature on RTS measurement in DEA is rapidly growing. Returns-to- scale and scale efficiency can lead to significant and long-lasting implications for management and politics. Furthermore, RTS classification can be used to decide on mergers and acquisitions. Following the description of the most common DEA models and their technology different approaches to measure RTS are described and advantages and disadvantages are elaborated. The approaches are subdivided in qualitative and quantitative approaches and RTS measurement in cost-based and non- radial models. Additionally, sensitivity analysis for RTS measurement is being dealt with. Finally, an empirical application is provided to illustrate RTS measurement approaches discussed in the paper.