The euro (symbol: €; currency code: EUR) is the official currency of 21 of the 27 member states of the European Union. This group of states is officially known as the euro area, more commonly named the eurozone. The euro is divided into 100 euro cents. The currency is also used officially by the institutions of the European Union, by four European microstates that are not EU members, by one British Overseas Territory, as well as unilaterally by two European states that are not EU members. Outside Europe, a number of special territories of EU members also use the euro as their currency. The euro is used by 358 million people in the eurozone, in addition to those living in states and territories where the euro is also the sole official currency. Furthermore, over 200 million people worldwide use currencies pegged to the euro. It is the second-largest reserve currency as well as the second-most traded currency in the world after the United States dollar. As of December 2019, with more than €1.3 trillion in circulation, the euro has one of the highest combined values of banknotes and coins in circulation in the world. The name euro was officially adopted on 16 December 1995 in Madrid. The euro was introduced to world financial markets as an accounting currency on 1 January 1999, replacing the former European Currency Unit (ECU) at a ratio of 1:1. Physical euro coins and banknotes entered into circulation on 1 January 2002, making it the day-to-day operating currency of its original members, and by March 2002 it had completely replaced the former currencies. Before December 2002, the euro traded below parity with the US dollar; since then, it has traded near or above parity. On 13 July 2022, the two currencies briefly hit parity for the first time in nearly two decades, due in part to the Russian invasion of Ukraine. In the ten years ending 30 September 2025, the rate has averaged at about $1.00:€0.89.