Metrication in Ireland

Metrication in the Republic of Ireland happened mostly in the 20th century and was officially completed in 2005, with a few exceptions.

The island of Ireland gradually adopted the British imperial measurement system, fully replacing traditional Irish measure during the 19th century, and these units continued to be used after the independence of the Irish Free State (1922) and the establishment of the Republic of Ireland (1937/49). The Irish Free State joined the Metre Convention in 1925. In 1980 the European Union asked all of its member states to convert to the metric system, and in Ireland and the UK this process was originally to have been completed by 2009. Metrication succeeded in Ireland with the changeover fully completed in 2005, with some exceptions.

Metrication

During the First World War and after the Easter Rising, Charles A Stanuell, former President of the Statistical and Social Inquiry Society of Ireland, published a paper advocating the use of the metric system and a decimal currency in the UK, of which Ireland was then a part.

Metrication in Ireland began in the 1970s and by 2005 was completed, with the main exception being that the imperial pint (568 ml) is still used in eateries and pubs for reasons of tradition. The phrase a "glass of beer" is a colloquial expression for a half-pint (284 ml). All other loose goods sold by volume must be sold using metric units.

Distances shown on directional road signs had displayed kilometres since the 1970s but road speed limits were in miles per hour until 20 January 2005, when they were changed to kilometres per hour.