The article focuses on the problem of evaluation of new markets in a circular economy, substantiating the need to assess not only economic performance, but also green utility in the process of making managerial decisions. The article proposes an algorithm for calculating the complex Index of Economic and Green Market Utility (IEGMU) for the region in the field of car sharing. It covers such indicators as market capacity and dynamics, the level of impact on the traditional automotive sector, as well as the green effect, which includes the reduction of carbon dioxide emissions, product (vehicle) consumption, and pressure on transport infrastructure. The advantage of the proposed algorithm is the possibility of using matrix analysis to determine the stage of development of each market. As an approbation, the article presents the calculation of the index for such regions as North America, Europe and Asia.