Abstract
While Circular Economy (CE) adoption is growing worldwide, its systematic assessment remains a challenge. The aim of this paper is to shed light on strengths and weaknesses of firm-level CE assessment tools and to theorize on the CE assessment issue. Four tools were selected and compared based on literature findings as well on a case study analysis on Italian SMEs. The main results indicate that the tools can be improved in terms of transferability, confirmability, understanding and generality. Accordingly, this study provides suggestions to improve the development of tools, that are of relevance for both theory and management practice.