Using a sample of 27 currencies, we empirically test the role of a large set of determinants potentially underlying currencies' share in the international currency system, providing, to the best of our knowledge, the most comprehensive study of this kind so far. We propose a new global indicator that quantifies the international use of currencies on the basis of three dimensions—medium of exchange, unit of account and store of value. From a range of indicators including openness, financial development and institutional development indicators, we uncover several variables that are significant in explaining the international status of currencies, hence contributing to understanding the role of the determinants shaping the international currency system. We also investigate the long‐run equilibrium values for currency shares, allowing us to score currencies on the basis of the potential stemming from the determinants. We contribute to the debate on international currencies' prospects, not only by looking at much discussed currencies such as the US dollar, the euro and the Chinese renminbi, but also by uncovering potential of emerging currencies. This knowledge is of the utmost importance for the debate on the reform of the international monetary system—from the point of view of academics, policymakers and market practitioners.