Enterprise Social Networks (ESN) are gaining increasing attention both in academia and practice. ESN enable various benefits in a company, which are assessed in success measurement models. A wide range of benefits focusing on social aspects has recently been identified clustered to an IT capability named Social Capital by Wehner et al. (2017a). For example, using the ESN enables employees to gain influence in the corporate community. Those benefits cannot be assessed using existing ESN success measurement models and can, thus, hardly be managed. Hence, the aim of this paper is to develop a measurement model focusing on the latter-named capability. We instantiate the Design Science approach and develop a measurement model focusing on the capability Social Capital. As a result, we identify 32 methods and metrics. Their applicability is demonstrated on an ESN dataset provided by a company. As a last step, we evaluate the model in an interview with a board member of this company. Conducting this research, we show that our model analyzes ESN success from a different perspective complementing existing success measurement models. Further, our model discloses social aspects used to make decisions to better manage an ESN.