Social impact measurement (SIM) is increasingly relied upon by entrepreneurs, investors, and governments to administer social change efforts. Yet, the application of SIM suffers with a recurrent gap between theory and practice: although SIM methods are designed based on rigorous scientific principles, unintended consequences on employees, beneficiaries, and desired outcomes continue to be observed. To explain these inconsistencies and support SIM as a critical enabler of positive social change, I problematize the longstanding assumption of the measurer being detached and neutral while applying measurement, and adopt a sensitizing, phenomenological, lens to instead investigate how individuals experience using SIM to administer social change. Specifically, I leverage a 6-year qualitative inductive study of stakeholders’ experiences applying SIM to administer a large-scale social change initiative, UK’s Coventry City of Culture 2021. I find that peoples’ first-hand accounts of SIM detail it as: 1) different to traditional measurement (partnership rather than transaction based, inclusive instead of exclusive of diverse voices, and solution rather than target focused), 2) as requiring specific skills (reflexivity and responsiveness), and 3) as challenging to convey to others (due to risk-aversity and low confidence). I theorize that these experiences outline a particular SIM skill acquisition model, and offer implications for scholarship on embodied management practices, and expertise development for social change. Practically, this study sheds light on SIM design and implementation.