Metrication timeline

Contrary to popular belief, the adoption of the metric system as the primary system of weights and measures in the UK is not a recent trend. Nor is it particularly to do with the European Union. Indeed, as the timeline below demonstrates, the quest for a single, rational system of measurement goes back to Magna Carta.

1215 Magna Carta requires “one measure” of wine, corn and cloth throughout the realm; and similarly for weights.
1668 Bishop John Wilkins, in England, publishes a proposal for a universal decimal system of measurement.
1670 Gabriel Mouton, in France, proposes a decimal measurement system.
1707 Treaty of Union extends English standard weights and measures to Scotland
1790 French National Assembly sends delegates to Britain, Spain and the United States to propose cooperation in units of measurement. Cooperation is rejected by Britain.
1795 Republic of France adopts French Academy of Sciences recommendation for a decimal Metric System.
1799 The platinum standards for metre and kilogram defined for decimal Metric System
1824 Weights and Measures Act phases out many traditional units and establishes the standard imperial system.
1861 A committee of the British Association for Advancement of Science (BAAS) including William Thomson (later Lord Kelvin), James Clerk Maxwell and James Prescott Joule introduced the concept of a coherent system of units which is fundamental to the modern metric system. They proposed the metre, gram and second as base units.
1862 Commons Select Committee unanimously recommends adoption of metric units for public administration.
1864 Weights and Measures Act legalises metric units only for ‘contracts and dealings’.
1873 A BAAS committee proposes centimetre, gram, second (CGS) base units using prefixes from micro to mega. They also propose a unit of electrical resistance (later named the ohm).
1875 Metre Convention established by diplomatic treaty to co-ordinate world metrology. International Bureau of Weights and Measures (BIPM) established.
1881 The first International Electrical Congress adopts various BAAS recommendations on electrical units (in the metric system).
Commons Select Committee recommends:
  • immediate authorising of metric units for all purposes
  • that the metric system becomes compulsory after 2 years
  • that the metric system be taught in elementary schools
1896 Weights and Measures (Metric System) Act legalises metric system for all purposes, but does not make it compulsory
1904 House of Lords votes for compulsory change to metric system, but Bill fails in House of Commons.
1914 The UK Met Office follows the lead of the International Meteorological Organisation (forerunner of the World Meteorological Organisation) and adopts the millimetre as the official standard unit of rainfall measurement.
1939 Davidson Committee proposes unified and metrically-based National Grid as common framework for Ordnance Survey mapping. Adopted 1940.
1951 Board of Trade committee recommends ‘organised change’ to metric system. Report seen as premature and not implemented.
1959 British and US inches (which were different) standardised as exactly 2.54 cm.
1963 Weights and Measures Act redefined the basic measures of the ‘yard’ and the ‘pound’ in terms of the ‘metre’ and the ‘kilogram’. Many of the old imperial measures were abolished (drachm, scruple, minim, chaldron, quarter, rod, pole, perch, and a few more). Imperial units are now defined in terms of metric.
1965 At the request of industry, President of Board of Trade announces that the metric system will be adopted with a target of completion within 10 years (i.e. 1975). Commonwealth and other countries decide to follow Britain’s example.
1968 Metrication Board established. However Board restricted to providing information and not permitted to promote benefits of the metric system.
1970 Re-surveying of UK begins to include metric elevations in Ordnance Survey maps.
1971 British currency decimalised. The much-feared changeover proved to be well organised and smooth. Massive Government information campaign to prepare the public for change.
1972 White Paper on Metrication advocates gradual not compulsory change.
1973 UK enters EEC and reaffirms commitment to adopt metric system.
1974 Metric system required to be taught in British schools. Metric packaging begins.
1979 New Government abolishes Metrication Board.
1980 Most Commonwealth countries have completed metric conversion. Britain lags behind significantly.
1988 British scientist Dr Terry Quinn appointed as Director of International Bureau of Weights and Measures (BIPM)
1989 EEC agrees UK request to secure delay in implementation of some aspects of the metric system
1995 UK regulations require packaged goods sold in Britain to be labelled in metric units. Negligible information provided to public.
2000 UK Regulations require goods sold from bulk to be measured and priced at the point of sale using metric units. Negligible information provided by Government to help public use metric units.
2004 Prof Andrew Wallard, former Chief Metrologist of UK’s National Physical Laboratory becomes Director of BIPM
2009 EU amends Directive to permit “supplementary indications” alongside metric units. Also withdraws requirement for UK to “fix a date” to convert road signs to metric units. Acre is phased out for land registration.