While all EU Member States can join the group's monetary union, the euro area, some members are far more ready for the adop-tion and use of the single European currency. Here, we construct a new Monetary Union Readiness Index (MURI) for the EU Member States. The theoretical framework of the index is built on the eco-nomic theory of Optimal Currency Areas and EU regulations such as the Treaty and the Maastricht criteria, and the Regulation on the Macroeconomic Imbalance Procedure. The index measures (i) nomi-nal convergence, (ii) real convergence, and (iii) macroeconomic sta-bility. The MURI Index provides an easy to use real-time policy tool to evaluate both candidate and current euro area members. Hence, it complements, aggregates and communicates key information in annual convergence reports and in official statistics. Our evaluation finds that Austria, Finland, Denmark, Sweden and Germany showed the highest level of compliance with the different euro area criteria in 2018, while Greece, Cyprus, Romania, Spain, and Italy were the least compliant.