Editing Metrication (section)

===United Kingdom (1824–present)===
{{Main|Metrication in the United Kingdom}}

The [[Weights and Measures Act 1824]] ([[5 Geo. 4]]. c. 74) imposed one standard 'imperial' system of weights and measures on the British Empire.<ref>{{cite web
|url = http://www.parliament.uk/about/living-heritage/transformingsociety/tradeindustry/industrycommunity/keydates/
|title = Industry and community – Key dates
|publisher = United Kingdom Parliament
|access-date = 28 March 2011
|archive-date = 6 November 2010
|archive-url = https://web.archive.org/web/20101106184932/http://www.parliament.uk/about/living-heritage/transformingsociety/tradeindustry/industrycommunity/keydates/
|url-status = live
}}</ref> The effect of this act was to standardise existing British units of measure rather than to align them with the metric system.

During the next eighty years a number of parliamentary select committees recommended the adoption of the metric system, each with a greater degree of urgency, but Parliament prevaricated. A select committee report of 1862 recommended compulsory metrication, but with an "Intermediate permissive phase"; Parliament responded in 1864 by legalising metric units only for 'contracts and dealings'.<ref name="Hyttel">{{Cite thesis
 |degree      = BA
 |title       = Working man's pint – An investigation of the implementation of the metric system in Britain 1851–1979
 |url         = http://ukma.org.uk/sites/default/files/hyttel_metrication.pdf
 |author      = Frederik Hyttel
 |date        = May 2009
 |publisher   = Bath Spa University
 |location    = [[Bath, Somerset|Bath]], United Kingdom
 |access-date  = 29 March 2011
|archive-url  = https://web.archive.org/web/20160306063341/http://ukma.org.uk/sites/default/files/hyttel_metrication.pdf
 |archive-date = 6 March 2016
|url-status     = dead
 |df          = dmy-all
}}</ref> The United Kingdom initially declined to sign the [[Treaty of the Metre]], but did so in 1883. Meanwhile, British scientists and technologists were at the forefront of the metrication movement – it was the [[British Association for the Advancement of Science]] that promoted the [[CGS system of units]] as a coherent system<ref name="SIBrochure">{{SIBrochure8th}}</ref>{{rp| 109}} and it was the British firm [[Johnson Matthey]] that was accepted by the CGPM in 1889 to cast the international prototype metre and kilogram.<ref name="CGPMprototypes">{{cite journal |last1=Jabbour |first1=Z.J. |last2=Yaniv |first2=S.L. |title=The kilogram and measurements of mass and force |journal=Journal of Research of the National Institute of Standards and Technology |date=January 2001 |volume=106 |issue=1 |pages=25–46 |doi=10.6028/jres.106.003 |pmid=27500016 |pmc=4865288}}</ref>

In 1895, another parliamentary select committee recommended the compulsory adoption of the metric system after a two-year permissive period. The [[Weights and Measures (Metric System) Act 1897]] ([[60 & 61 Vict.]] c. 46) legalised the metric units for trade, but did not make them mandatory.<ref name = Hyttel/> A bill to make the metric system compulsory to help the British industrial base fight off the challenge of the nascent German base passed through the House of Lords in 1904, but did not pass in the House of Commons before the next general election was called. Following opposition by the Lancashire cotton industry, a similar bill was defeated in the House of Commons in 1907 by 150 votes to 118.<ref name = Hyttel/>

In 1965, the UK began an official programme of metrication, and as of {{currentyear}}, in the [[United Kingdom]] the metric is the official measurement system for all regulated trading by weight or measure purposes, however the imperial [[pint]] remains the sole legal unit for milk in returnable bottles and for draught beer and cider in British pubs. Imperial units are also legally permitted to be used alongside metric units on food packaging and price indications for goods sold loose.<ref>{{Cite web |title=Weights and measures: the law |url=https://www.gov.uk/weights-measures-and-packaging-the-law |access-date=2024-02-12 |website=GOV.UK |language=en |archive-date=30 October 2023 |archive-url=https://web.archive.org/web/20231030170848/https://www.gov.uk/weights-measures-and-packaging-the-law |url-status=live }}</ref> The UK government undertook a "Choice on units of measurement: consultation response", and found just over 1% of respondents wish to revert to an increase the use of imperial units,  and as such kept the current regulations on the sale of goods.<ref>{{Cite web |title=Choice on units of measurement: consultation response |url=https://www.gov.uk/government/consultations/choice-on-units-of-measurement-markings-and-sales/outcome/choice-on-units-of-measurement-consultation-response |access-date=2024-02-12 |website=GOV.UK |language=en |archive-date=20 January 2024 |archive-url=https://web.archive.org/web/20240120162306/https://www.gov.uk/government/consultations/choice-on-units-of-measurement-markings-and-sales/outcome/choice-on-units-of-measurement-consultation-response |url-status=live }}</ref>

In addition imperial units may be used exclusively where a product is sold by description, rather than by weight/mass/volume: e.g. television screen and clothing sizes tend to be given in inches only, but a piece of material priced per inch would be unlawful unless the metric price was also shown.

The general public still use imperial units in common langange for their height and weight, and imperial units are the norm when discussing longer distances such as journeys by car, but otherwise metric measurements are often used.{{citation needed|date=August 2022}}