This article empirically applies, tests, and refines a conceptual framework that articulates three dimensions of transformative impact and transformative capacity: depth, width, and length. This responds to the need for a more precise conceptual language to describe these terms and operationalize them in a way that is useful for practitioners in social innovation networks. By applying this framework in diverse cases of social innovation networks, we demonstrate how the framework can serve to identify and assess transformative impacts and the capacities needed to bring about these impacts. Our findings include 1. empirical substantiations, 2. refinements, and 3. interaction effects among the elements of the framework. We also subjected the framework to an appraisal by practitioners in social innovation networks regarding the recognizability of the framework elements and usefulness for practice. The framework was generally perceived as very meaningful and valuable for social innovation practitioners as a way to understand, assess, strategically design and evaluate their transformation efforts. Drawing on feedback by practitioners, we offer recommendations for further research and development of the framework to improve its usefulness in practice.