Transparency, accountability, participation and inclusiveness are central concepts in the literature on public administration. They are considered qualities that enable administrative bodies to share power with social and political actors and strengthen their democratic nature. These qualities have also been recognized as crucial for regulatory bodies, especially because of the technocratic nature of these bodies. Despite their importance, the literature provides limited measurement of these qualities, which means that neither the extent to which regulatory bodies are formally required to provide for transparency, accountability, participation and inclusiveness nor the extent to which they do so in practice can be captured and compared adequately. To address this gap, we develop measures of 'de jure' and 'de facto' transparency, accountability, participation and inclusiveness from a novel data set of 49 national, subnational and supranational regulatory bodies in three sectors (data protection, food safety and finance) and in nine countries. We use Item Response Theory methods to validate the indicators and their relative weight in the measure, providing a tool substantiated by comprehensive data to assess how regulatory bodies enhance democratic governance.