The paper introduces three measures of the international financial sector and presents the ranking of countries based on these measures. The International Finance Index measures the absolute size, the International Finance Location Quotient measures the level of development, and the International Finance Diversity Index captures the degree of diversity and specialisation of a country's international financial services sector. Empirical analysis is conducted for 41 countries using the data from the BIS, the WFE, the IMF, and stock exchanges on cross-border loans and deposits, international debt securities, cross-listed stocks, as well as foreign exchange and OTC derivatives. The analysis confirms the leading position of the UK in international finance, and a relatively weak position of Japan. The paper also discusses the applicability of the International Finance Index and its derivatives in academic and policy research concerned with international financial development, and competition between financial centres.