Search papers

The EU & Weights and Measures


EU legislation on weights and measures has often proved controversial in the United Kingdom.  The issues over the remaining imperial measures used in the United Kingdom and the Republic of Ireland were resolved in 2007, and with effect from the beginning of 2010, their indefinite use is guaranteed.

This briefing paper explains the EU’s regulations on metrication and the exceptions that have been made.


Metrication in Europe

The first known proposal for a metric system of measurement was apparently made in 1688 by an Englishman, John Wilkins.  The idea was adopted in France after the Revolution in 1791 and has become the standard system of measurement in all but three countries of the world (Burma, Liberia and the United States).  Some countries, such as the United Kingdom, permit or require other systems of measurement for some purposes, for examples miles in the UK, and metric measures are in practice widely used in the United States.  Some non-metric measures are still used in certain sectors throughout the world; examples include knots and nautical miles in civil aviation.  The preference for metric measurements over other systems derives from the greater accuracy of the metric system, its simplicity and its near universal use.

The six founder Member States of the European Communities were all metric countries so it was not surprising that the Community adopted regulations in 1971 requiring the use of metric measurements for Community purposes (such as the internal market).  The regulations were necessary because there had been changes in the metric measurements used in some economic sectors, notably science and engineering, and more than one standard existed.

The EC rules required the use of the International System of Units, now the global standard in metric systems.  Exemptions were made in those regulations for certain sectors, such as air and sea traffic and railways, as these sectors were governed by wider international agreements.


The British Situation

When the United Kingdom negotiated entry to the Communities in 1971/2 metric measures were not an issue as the UK (and the Republic of Ireland) had decided in 1965 to make metric measurements compulsory within 10 years (metric measurements had been legal in the UK since 1896).  However, despite the introduction of metric measurements in education, the decimalisation of the currency in 1971 and various other changes, the progress of metrication slowed down.  In particular, under public pressure the British Government abandoned plans to replace miles on road signs with kilometres.

The subsequent decision to abolish the Metrication Board in 1980 and effectively abandon further extension of the metric system gave the UK a problem as it had an obligation to implement the 1971 EU directive on weights and measures.  The UK Government sought an extension of time for the implementation of the 1971 directive and this was agreed in 1980.  The new rules permitted the continued use of certain imperial measures until the end of 1989.  Miles and related measurements on road signs, pints for the sale of milk, draught beer and cider, acres in land registration and troy ounces for precious metals would be able to be used until a date to be fixed by the Council.  Ireland also benefited from these new regulations as progress towards metrication had slowed there as well.

The deadlines agreed as a result of the 1980 directive were subsequently extended – although the acre was dropped by the UK – and the pint, the mile and troy ounce continued in use in Britain and Ireland.

Despite these exemptions, some protestors in Britain objected to the use of metric measurements at all, such as for the sale of fruit and vegetables.  Their attempts at using imperial only scales resulted in court proceedings in a number of cases.


The US Dimension

US businesses were concerned by 2005 that they would be required to put metric only labels on goods they sold in the EU; they had been using dual labels with metric and imperial measurements by agreement with the EU for some years.  Lobbying by the US Department of Commerce and US businesses contributed to the Commission’s decision in 2007 to call a halt to further attempts to make metrication compulsory and to allow dual labelling to continue indefinitely.


The 2009 Regulations

In March 2009 a new directive (2009/3/EC) was agreed amending existing EU regulations on metric measurements.  The new regulations permitted:

  • the indefinite use of dual labelling in metric and imperial measurements;
  • the indefinite use of non-metric measurements where no metric ones exist, such as bytes in computing;
  • the indefinite use by the United Kingdom and by the Republic of Ireland of the pint, the mile and the troy ounce for certain specified uses.

The regulations came into force on 1 January 2010.  No new time limits were imposed and so these decisions effectively became derogations and not, as they had previously been regarded, as transitional measures.

In the UK, the regulation means that the pint will continue to be used for the sale of milk, draught beer and cider, the mile for road signs and speed measurement and the troy ounce for the sale of precious metals.