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Weights and Measures Acts UK
Laws of the British Parliament determining the regulation of weights and measures
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Bronze Yard No.11, the official standard of length for the United States between 1855 and 1892, when the Treasury Department formally adopted a metric standard. Bronze Yard No.11 was forged to be an exact copy of the British Imperial Standard Yard, which was ruined in 1834 during the Burning of Parliament. Both were line standards: the yard was defined by the distance at 62°F between two fine lines drawn on gold plugs (closeup, top) installed in recesses near each end of the bar.
Weights and measures acts are acts of the British Parliament determining the regulation of weights and measures. It also refers to similar royal and parliamentary acts of the Kingdoms of England and Scotland and the medieval Welsh states. The earliest of these were originally untitled but were given descriptive glosses or titles based upon the monarch under whose reign they were promulgated. Several omnibus modern acts are entitled the Weights and Measures Act and are distinguished by the year of their enactment.
There have been many laws concerned with weights and measures in the United Kingdom or parts of it over the last 1,000 or so years. The acts may catalogue lawful weights and measures, prescribe the mechanism for inspection and enforcement of the use of such weights and measures and may set out circumstances under which they may be amended. Modern legislation may, in addition to specific requirements, set out circumstances under which the incumbent minister may amend the legislation by means of statutory instruments. Prior to the Weights and Measures Act 1985, weights and measures acts were only concerned with trade law where the weight or size of the goods being traded was important. The 1985 act, however, had a broader scope, encompassing all aspects covered by the European Economic Community (EEC) European Commission directive 80/181/EEC.
As of 25 April 2012, the current primary legislation in the United Kingdom is the 1985 Act, which was last amended by statutory instrument in 2011. Statutory instruments made under the authority of the Act do not amend the Act per se, but regulate particular areas covered by the Act.
Historically, many units had various customary definitions—by locality or trade, for example. Where these units also had a standard, legally defined definition, such as given in a weights and measures act, this was known as the statute measure. So a land area might be given as 24 acres—statute measure, to clarify that it was the acre defined in statute, rather than a customary acre of a different size, that was being used. Units that had statute-defined measures as well as customary measures were the acre, mile, perch, pole and ton. The level of legal enforcement of statute measures achieved between the mid nineteenth and the beginning of the twentieth centuries meant that only "statute mile" and "statute ton" needed qualifying beyond then. The statute mile still needed to be differentiated from the nautical mile, but the others, and the term "statute measure" itself, are now only used in a historical context.
Metric units of measure
The Weights and Measures Act 1897 provided that metric units could be used in addition to the traditional imperial units for purposes of trade. In practice, the actual choice of units was restricted by price marking orders which listed packaging sizes and pricing structures that might be used in specific circumstances. For example, as of April 2012, wine for consumption on premises may only be sold in 125, 175, and 250 mL glasses while draught beer may only be sold as 1⁄3, 1⁄2, or 2⁄3 pint and integer multiples of 1⁄2pint. Prior to 1973, when the United Kingdom joined the EEC, such specifications were almost all in imperial units.
As part of its attempt to harmonise units of measure between the member states of its Internal Market, the European Commission (EC) issued directive 80/181/EEC which set out the units of measure that should be used for what it called "economic, public health, public safety, and administrative" purposes. To comply with this directive, the Weights and Measures Act 1985 extended the scope of Trading Standards responsibilities from just matters related to trade to all aspects of the directive. For example, it was the Trading Standards Office that criticised the use of sub-standard weighing machines in NHS hospitals.
To help ease the EC's desired transition from sole use of imperial units to sole use of metric units, the directive permitted the use of what were termed "supplementary indicators"--the continued use of imperial units alongside the metric units catalogued by the directive (dual labelling). The initial intention was to prohibit dual labelling after the end of 1989, with metric units only being allowed after that date. This deadline was later extended: first to the end of 1999, then to the end of 2009. Finally, in 2007, the European Union (EU, as it had become) and the EC confirmed that the UK would be permitted to continue indefinitely to use imperial units such as pints, miles, pounds and ounces as at present. The Gloucestershire County Council Trading Standards Department confirmed the EU ruling that the previous deadline for ending dual labelling had been abolished.
There are still a few cases where imperial units are required to be used and where metric units are not permitted within the scope of the Weights and Measures Act, such as the pint for the sale of draught beer and cider, and miles and yards for distances on road signage. Milk in returnable containers may be sold by the pint and the troy ounce may be used for the sale of precious metals. In addition, British law specifies which non-metric units may be used with dual labelling (for example the imperial gallon, but not the US gallon).
And ?an?e án m?net ofer ealne þæs c?ni?es an?eald? ? þone nan man ne forsace? ? ?an?e án ?emet ? án ?e?ihte? s?ilce man on Lunden-b?ri? ? on ?intan-ceastre healde? ? ?a seo ?æ?e ?ulle to ?cxx? p?. ? nan man hi? undeoror ne s?lle? ? ?if h?a hi þonne undeoror s?lle? oþþe ea?un?a oþþe dearnun?a? ?ilde æ?ðer þam c?n?e ?xl? scillin?á. ?e seþe hi s?lle ?e seþe hi b?c?e:?
And let one money pass throughout the king's dominion; and that let no man refuse: and let one measure and one weight pass; such as is observed at London and at Winchester; and let the wey of wool go for 120 pence; and let no man sell it cheaper; and if any one sell it cheaper, either publicly or privately, let each pay 40 shillings to the king, both him who sells it, and him who buys it.
The statute also survives in a few other Old English and Latin copies, some which omit mention of London and describe "the measure held at Winchester", an indication that a standard ell or yard was nominally in use:
de moneta, et mensura, et pondere.
on money, and measure, and weight.
Et sit una moneta per totum regis imperium, et nemo sonet eam; et mensura, sicut apud Wincestriam habetur. Et eat pondus lane pro dimidia libra, et nemo carius vendat eam.
And let there be one money through all the king's dominion; and let no man refuse it; and [one] measure, as is held at Winchester. And let the weight of wool go for a half-pound, and no one sell it more dearly.
John Quincy Adams's 1821 report on the history of English weights and measures notes of this act that "it was never observed".
Assize of Measures
It is established that woollen cloths, wherever they be made, be made of the same width, to wit, of two ells within the lists [selvages], and of the same good quality in the middle and at the sides. Also the ell shall be the same in the whole realm and of the same length and the ell shall be of iron.
Acts of Parliament
Statutes of uncertain date
The statutes of uncertain date (Latin: Statuta temporis incerti) are generally dated to the mid-to-late 13th century.
"By the Consent of the whole Realm of England, the measure of our Lord the King was made; that is to say, That the English Peny, called a Sterling, round and without clipping, shall weigh xxxii Wheat Corns in the midst of the Ear, and xx d. do make an Ounce, and xii Ounces one Pound, and Viii Pound do make a Gallon of Wine, and viii Gallons of Wine do make a London Bushel, which is the Eighth Part of a Quarter. Forasmuch as in our Parliament holden at Westminster, in the first Year of our Reign, we have granted that all good Statutes and Ordinances made in Times of our Progenitors aforesaid, and not revoked, shall be still held, we have caused, at the Request of the Bakers of our Town of Coventry, that the Ordinances aforesaid, by tenor of these Presents, shall be exemplified. In Witness whereof, &c. Whitness the King at Westminster, the xxii Day of March."
Also known as the Tractatus de Ponderibus, Compositio de Ponderibus ("The Composition of Weights"), Assisa de Ponderibus et Mensuris ("Assize of Weights and Measures"). It is important to note when reading it that, in the Latin and English text, "hundred" (and the Latin numeral c.) is used for four separate concepts: the Germanic long hundred of 120, the short hundred of 100, several units of either value, and a separate unit (the hundredweight) of 108 pounds.
The form in which it appears in Cotton MS Claudius D2 where it is dated to 31 Edw. I (1303) is:
Tractatus de Ponderibus et Mensuris.
Per Ordinacionem tocius regni Anglie fuit mensura Domini Regis composita videlicet quod denarius qui vocatur sterlingus rotundus & sine tonsura ponderabit triginta duo grana frumenti in medio Spice.
Et uncia ponderabit viginti denarios. Et duodecim uncie faciunt libram London. Et duodecim libre & dimid’ faciunt petram London. Et octo libre frumenti faciunt galonem. Libra continet viginti solidos. Et octo galones faciunt bussellum London. Saccus lane debet ponderare viginti & octo petras & solebat ponderare unam summam frumenti & ponderat sextam partem unius carri de plumbo. sexies viginti petre faciunt carrum plumbi scilicet magnum carrum London’ set carrus del Peek est multo minus.
Item carrus plumbi constat ex triginta fotmallis & quodlibet fotmal continet sex petras duabus libris minus. Et quelibet petra habet duodecim libras & quelibet libra constat ex viginti quinque solidis in pondere. summa librarum in le fotmal lxx. summa petrarum in le Carre viii. xx. & xv. petre & probetur per sexies triginta que sunt novies viginti set in quolibet fotmal subtrahuntur due libre a predicta multiplicacione qe sunt lx. libre constituentes quinque petras. Ita sunt in le Carre viii. xx. xv. petre. secundum vero quosdam alios le Carre consistit ex xii. Weyes & hoc secundum troni ponderacionem. Weya enim tam plumbi quam lane lini sepi casei ponderabunt xiiii. petras.
Et duo Weye lane faciunt saccum. Et xii. sacci faciunt le last. Last vero allecis continet decem miliaria. Et quodlibet miliare continet x.c. Et quodlibet c. continet vi. xx.
Item last coriorum constat ex viginti dacris & quodlibet dacre constat ex decem coriis.
Item dacre Cirotecarum constat ex decem paribus dacre vero ferrorum equorum constat ex viginti ferris.
Item duodena cirotecarum pergameni & alute continet in suo genere xii. pelles vel xii. paria cirotecarum.
Item centena cere zucarii piperis cumini amigdalarum & alome continet xiii. petras & dimid’ & quelibet petra continet viii. li. summa librarum in centena cviii. libre. Et constat centem ex v. xx. Et quelibet libra ex viginti quinque solidis. Et sciend’ quod quelibet libra de denariis & speciebus utpote in electuariis consistit solummodo ex pondere xx. s. Libra vero omnium aliarum rerum consistit ex viginti quinque solidis. Uncia vero in electuariis consistit ex viginti denariis. Et libra continet xii. uncias. In aliis vero rebus libra continet quindecim uncias. uncia est hinc inde in pondere viginti denariorum. Centena lini & Canabi & linee tele consistit ex cent’ ulnis. Et quelibet Centena consistit ex vi. xx. Centena vero ferri & solidorum constat ex v. xx. Garba asseris constat ex triginta peciis. Duodena ferri ex sex peciis Item seem vitri constat ex xxiiii. petris & quelibet petra constat ex quinque libris. Et ita continet le seem vi. xx. libras.
Item binda anguillarum constat ex decem stiks. Et quelibet stik ex viginti quinque anguillis Binda pellium continet xxxii. timbr’ senellio cuniculorum & grisi continet quadraginta pelles. Cheef de fustiano constat ex tresdecim ulnis Caput sindonis ex decem ulnis Le rees allecium continet quindecim glenes. Et quodlibet glene continet viginti quinque capita. Item centene Mulvellorum & durorum piscium constat ex viii. xx.
Per Ordinance of the whole realm of England the measure of the King is composed namely of a penny, which is called a sterling, round & without clipping, weighs thirty-two grains of wheat in the middle of the Ear.
And an ounce weighs twenty pence. And twelve ounces make a pound of London. And twelve & a half pounds make a stone of London. And eight pounds of wheat make a gallon. Pound contains twenty shillings. And eight gallons make a bushel of London. Sacks of wool should weigh twenty-eight stones and usually weighs of wheat and weighs a sixth part of a load of lead. Six times twenty stone, make a load of lead, to wit the great load of London, but the load of the Peak is much less.
Also loads of lead consist of thirty fotmals, and each fotmal contains six stones minus two pounds. And each stone consists of twelve pounds, and each pound consists of twenty-five shillings in weight. The sum of the pounds in the fotmal is 70. The sum of the stones in the Load is 175 stones and is proved by six times thirty which is nine score (180) except for each fotmal subract two pounds multiplied as before (x30) which is 60 pounds constituting five stones. So there are in the load 175 stones. But according to some others the load consists of 12 Weys and this is according to troni weight, Wey for both lead and wool linen tallowcheese weighs 14 stones.
The original Tractatus was written in Latin. Some later English translation copies contain differences that change the meaning. One of the copies of the Tractatus contains the first use of the word avoirdupois in England. However, the word does not refer to a weight system but to a class of goods: viz., heavy goods sold by weight rather than by capacity, count, or other means. However, it does not count as the first occurrence of the word in English.
Ordinatum est quod tria grana ordei sicca et rotunda faciunt pollicem, et duodecim pollices faciunt pedem, tres pedes faciunt ulnam, quinque ulne et dimidia faciunt perticam, et quadraginta pertice in longitudine, et quatuor in latitudine, faciunt unam acram.
It is ordained that 3 grains of barley dry and round do make an inch, 12 inches make 1 foot, 3 feet make 1 yard [lit. ell], 5 yards and a half make a perch [i.e., a rod], and 40 perches in length and 4 in breadth make an acre.
"And be it remembered that the iron yard of our Lord the King containeth 3 feet and no more, and a foot ought to contain 12 inches by the right measure of this yard measured, to wit, the 36th part of this yard rightly measured maketh 1 inch neither more nor less and 5 yards and a half make a perch that is 16 feet and a half measured by the aforesaid yard of our Lord the King."
This document seems to have had the effect of redefining the yard, foot, inch, and barleycorn to 10⁄11 of their previous values, but leaves the rod and acre unchanged. The rod thus became 16½ feet instead of 15.
There shall be but one Measure throughout the Realm.
Una Mensura vini sit per totum regnum nostrum & una mensura cervise & una mensura bladi scilicet quarter’ London’ & una latitudo pannorum tinctorum Russettorum & haubergettorum scilicet due ulne infra Listas. De ponderibus vero sit sicut de mensuris.
One measure of Wine shall be through our Realm, and one measure of Ale, and one measure of Corn, that is to say, the Quarter of London; and one breadth of dyed Cloth, Russets, and Haberjects, that is to say, two Yards within the lists. (2) And it shall be of Weights as it is of Measures.
The Magna Carta of 1215 was not ratified by Parliament until 1225, by which time it had become substantially abridged. Chapter 35 of the Magna Carta of 1215 (which dealt with weights and measures) became chapter 25 of the Magna Carta of 1225.
Auncel Weight shall be put out, and Weighing shall be by equal Balance.
Enfement pur ce qe tres grant damage & desceit est fait au people par tant qe plusours marchantz usent dachater & poiser leines & autres marchandises par une pois qest appelle Aunsell’ Acorde est & establi qe celle pois appelle Aunsell’ entre achatour et vendour soit del tout ofte & qe chescun vend & achat par balances iffint qe les balances soient owels & les leines & autres marchandises owelment poisez par droit pois & qe le sak de leine ne poise qe vint & sys peres & chescun pere poise quatorze livres & qe lestater de la balance ne encline ne a lune partie ne al autre & qe le pois soit acordant al estandard del Escheker. Et si nul achatour face al encontre soit grevousement puny sibien a la seute de partie come a la seute nostre Seignur le Roi.
Item, Whereas great Damage and Deceit is done to the People, for that divers Merchants use to buy and weigh Woolls and other Merchandises, by a Weight which is called Auncel; it is accorded and established, That this Weight called Auncel betwixt Buyers and Sellers, shall be wholly put out; (2) and that every Person do sell and buy by the Balance, so that the Balance be even, and the Woolls and other Merchandizes evenly weighed by the right Weight, so that the Sack of Wooll weigh no more but 26 Stones, and every Stone to weigh 14 l. and that the Beam of the Balance do not bow more to the one Part than to the other; (3) and that the Weight be according to the Standard of the Exchequer. (4) And if any Buyer do the contrary, he shall be grievously punished, as well at the Suit of the Party, as at the Suit of our Lord the King.
Every Measure shall be according to the King's Standard; and shall be striked without Heap; saving the Rents of Lords.
Auxint come contenue soit en la Grande Chartre qe une mesure soit usee parmy tout Engleterre la quele chartre nad mie este tenu bien en ceo point avant ses heures si est acorde & assentu qe touz les mesures cest asavoir bussel dimid' bussel & peck galon potel & quart par toute Engleterre deinz fanchise & dehors soient acordauntz al estandard nostre Seignur le Roi & contiegne le quartre oet busselx par lestandard & nient pluis. Et soit chescune mesure de blee rase fanz comble sauvez les rentes & fermes des Seignurs queles soient avant ces heures. Et facent les purveours le Roi ma dame la Roigne & touz autres lours purveances par meismes les mesures rases & en meisme le manere Et a toutes les foitz qe mestier serra Nostre Seignur le Roi assignera certeines Justices en chescune countee denqueer & doier & terminer sur les pointz suisditz & de faire sur ce due punissement solone chescun trespas siebien a la seute de partie come a la seute le Roi. Iffint totes soitz qe toutes maneres des franchises soient sauvez as Seignurs en toutz pointz saunz nul emblemissement ent faire en quecumqe manere.
Item, Whereas it is contained in the Great Charter, that one Measure shall be throughout England, which Charter hath not been well kept and holden in this Point in Times past; (2) it is accorded and assented, That all the Measures, that is to say, Bushels, Half-bushels, Peck, Gallon, Pottle, and Quart, throughout England, within the Franchises and without, shall be according to the King's Standard; (3) and the Quarter shall contain Eight Bushels by the Standard, and no more. (4) And every Measure of Corn shall be striken without Heap, saving the Rents and Ferms of Lords, which shall be measured by such Measures as they were wont in Times past. (5) And the Purveyors of the King, of the Queen, and all other, shall make their Purveyances by the same Measure striked in the same Manner, and at all Times that shall be needful. (6) And our Lord the King shall assign certain Justices in every County to inquire, hear, and determine upon the Points aforesaid, and upon the same to do Punishment according to the Trespass, as well at the Party's Suit, as at the King's; (7) so always, that all Manner of Franchises be saved to the Lords in all Points without Blemish to be made in any Manner.
There shall be but one Weight, Measure and Yard throughout the Realm.
...un pois, un mesure, et un verge soit per tut la terre...
...one weight, one measure [of volume], and one [measuring] stick shall there be through all the land...
A chapter of the Statute of the Staple that provides for justices to be appointed to hear charges of measuring fraud at the staple ports. Those found guilty were liable for quadruple damages and 2 years' imprisonment.
"That the Measure of a Bushel contain viij. Gallons of Wheat, and that every Gallon contain viij. li. of Wheat of Troy Weight, and every Pound contain xij. Ounces of Troy Weight, and every Ounce contain xx. Sterlings, and every Sterling be of the Weight of xxxij. Corns of Wheat that grew in the Midst of the Ear of Wheat, according to the old Laws of this Land."
"And whereas heretofore the merchaunte paid for coynage of every pounde Towre of fyne gold weighing xi oz. quarter Troye ii s. vi d. Nowe it is determyned by the king's highness, and his said councelle that the foresaid pounde Towre shall be no more used and occupied but al maner of golde and sylver shall be wayed by the pounde Troye, which maketh xii oz. Troy, which exceedith the pounde Towre in weight iii quarters of the oz."
"XIV. And that all and every Broad Cloth and Clothes called Taunton Clothes, Bridgwaters, and other Clothes which shall be made after the said Feast in Taunton, Bridgwater or in other Places of like Sort, shall contain at the Water in Length betwixt twelve and thirteen Yards, Yard and Inch of the Rule, and in Breadth seven-Quarters of a Yard: (2) And every narrow Cloth made after the said Feast in the said Towns or elsewhere of like Sorts, shall contain in the Water in Length betwixt three and twenty and five and twenty Yards, Yard and Inch as is aforesaid, and in Breadth one Yard of like Measure; (3) and every such Cloth, both Broad and Narrow being well scowred, thicked, milled and fully dried, shall weigh xxxiv. li. the Piece at the least."
"XV. And that all Clothes named Check-Kersie and Straits, which shall be made after the said Feast shall contain being wet between seventeen and eighteen Yards, with the Inches as is aforesaid, and in Breadth one Yard at the least at the Water; and being well scowred, thicked, milled and fully dried, shall weigh xxiv. li. the Piece at the least."
"IX. Item, That every ordinary kersie mentioned in the said act shall contain in length in the water betwixt xvi. and xvii. yards, yard and inch; and being well scoured thicked, milled, dressed and fully dried, shall weigh nineteen pounds the piece at the least:..."
An Act touching the true melting, making and working of Wax.
"...fill and sell or cause to be filled or sold or offered to be sold any Barrel, Kilderkin or Firkin with Honey, for or in the Name of a Barrel, Kilderkin or Firkin containing less than two and thirty Wine Gallons the Barrel, sixteen Wine Gallons the Kilderkin, and eight Wine Gallons the Firkin; every Person and Persons so offending shall forfeit and lose for every Half Gallon so lacking five Shillings of English Money."
An act for the reformation of sundry abuses in clothes, called Devonshire kerjies or dozens, according to a proclamation of the thirty-fourth year of the reign of our sovereign lady the Queen that now is.
"(2) and each and every of the same Devonshire kersies or dozens, so being raw, and as it cometh forth off the weaver's loom (without racking, stretching, straining or other device to encrease the length thereof) shall contain in length between fifteen and sixteen yards by the measure of yard and inch by the rule, ..."
"...every round bushel with a plain and even bottom being eighteen inches and a half wide throughout and eight inches deep shall be determined a legal Winchester bushel according to the Standard of His Majesty's Exchequer."
An Act for continuing several Subsidies, Impositions and Duties and for making Provisions therein mentioned to raise Money by Way of Loan for the Service of the War, and other Her Majesty's necessary and important Occasions, and for ascertaining the Wine Measure.
...any Vessel containing two hundred thirty one cubical Inches and no more shall be deemed and taken to be a lawful Wine Gallon...
This statute is the origin of the US gallon, also known as the Queen Anne Gallon, Queen Anne Wine Gallon, or pre-1824 British gallon.
An Act for more effectually preventing Traders in exciseable Commodities from using false Weights and Scales and for explaining and amending several Acts of Parliament relating to Hackney Coaches and Chairs
An Act to explain and amend an Act made in the thirty-fifth Year of the Reign of his present Majesty, intituled, An Act for the more effectual Prevention of the use of defective Weights, and of false and unequal Balances.
An Act for ascertaining and establishing Uniformity of Weights and Measures.
And whereas not withstanding it is provided by the Great Charter, that there shall be but one Measure and one Weight throughout the Realm, and by the Treaty of Union between England and Scotland, that the same Weights and Measures should be used throughout Great Britain as were then established in England, yet different Weights and Measures, some larger, and some less, are still in use in various Places throughout the United Kingdom of Great Britain and Ireland, and the true Measure of the present Standards is not verily known, which is the Cause of great Confusion and of manifest Frauds : For the Remedy and Prevention of these Evils for the future, and to the End that certain Standards of Weights and Measures should be established throughout the United Kingdom of Great Britain and Ireland; be it therefore enacted ...
This is the origin of Imperial units. This statute repeals nearly all previous weights and measures legislation, listing them in chronological order (by regnal year but without dates) beginning with "ancient statutes of uncertain date."
Also known as the Weights and Measures Act 1835; originally entitled "An Act to repeal an Act of the Fourth and Fifth Year of His present Majesty relating to Weights and Measures, and to make other Provisions instead thereof".
Weights and Measures Act 1855 (18 & 19 Vict. c. 72)
An Act for legalising and preserving the restored Standards of Weights and Measures
The 1834 burning of Parliament had destroyed the physical standards referred to in earlier statues; the 1835 act ignored this fact. New copies were created in accordance with the advice of a scientific commission, and the 1855 act made them the "restored Standards".
...the Imperial Standard Pound Avoirdupois and shall be deemed to be the only Standard Measure of Weight from which all other Weights and other Measures having Reference...
Weights and Measures Act 1859 (22 & 23 Vict. c. 56)
An Act to amend the Act of the fifth and sixth years of King William the Fourth, chapter sixty-three, relating to weights and measures.
Metric Weights and Measures Act 1864 (27 & 28 Vict. c. 117)
An Act to render permissive the Use of the Metric System of Weights and Measures.
Weights and Measures Act 1878 (41 & 42 Vict. c. 49)
An Act to consolidate the Law relating to Weights and Measures.
The Act defines the four primary units of measurement as the metre or the yard (defined in terms of the metre) for length, and the kilogram or pound (defined in terms of the kilogram) for mass. The Act also requires standard physical examples to be maintained (known as "United Kingdom primary standards") for each of the four primary units.
In addition, the definitions of units which are multiples or sub-multiples of the primary units are defined, in terms of the primary units, and given as: mile, foot, inch, kilometre, decimetre, centimetre, millimetre, acre, square yard, square foot, hectare, decare, are, square metre, square decimetre, square centimetre, square millimetre, cubic metre, cubic decimetre, cubic centimetre, hectolitre, litre, decilitre, centilitre, millilitre, gallon, quart, pint, gill, fluid ounce, pound, ounce, ounce troy, tonne, kilogram, hectogram, gram, carat (metric) and milligram.
As originally enacted, the act also defined, in the same way, units which could not be used for trade as: furlong, chain, square mile, rood, square inch, cubic yard, cubic foot, cubic inch, bushel, peck, fluid drachm, minim, ton, hundredweight, cental, quarter, stone, dram, grain, pennyweight, ounce apothecaries, drachm, scruple, metric ton and quintal.
As of January 2020[update], following multiple amendments over the years since enactment, the metre, yard, kilogram and pound remain as the primary defined units and with the requirement to maintain the "United Kingdom primary standards" for them.
At the same time, all the imperial units, except pint and ounce troy (but including all of those which were originally defined as not to be used for trade) were reclassified as being available for use for trade as supplementary indications, namely: mile, furlong, chain, yard, foot, inch, square mile, acre, rood, square yard, square foot, square inch, cubic yard, cubic foot, cubic inch, bushel, peck, gallon, quart, gill, fluid ounce, fluid drachm, minim, ton, hundredweight, cental, quarter, stone, pound, ounce, dram, grain, pennyweight, ounce apothecaries, drachm, scruple and quintal. The tonne was also reclassified as being available for use for trade as a supplementary unit of measure,
^Thorpe, Benjamin (1840), "The Laws of King Edgar", Ancient Laws and Institutes of England; Comprising Laws enacted under the Anglo-Saxon Kings from Æthelbirht to Cnut, With an English Translation of the Saxon; The Laws called Edward the Confessor's; The Laws of William the Conqueror, and those ascribed to Henry the First: Also, Monumenta Ecclesiastica Anglicana, From the Seventh to the Tenth Century; And the Ancient Latin Version of the Anglo-Saxon Laws. With a Compendious Glossary, &c., London: Commissioners of the Public Records of the Kingdom, p. 113. (in Old English) & (in Latin) & (in English)
^Clarke, William (1767), The Connexion of the Roman, Saxon, and English Coins Deducing the Antiquities, Customs, and Manners of Each People to Modern Times; Particularly the Origin of Feudal Tenures, and of Parliaments: Illustrated throughout with Critical and Historical Remarks on Various Authors, both Sacred and Profane, London: W. Bowyer & J. Nichols, p. 150
^Ruffhead, Owen, ed. (1763a), The Statutes at Large, Vol. I: From Magna Charta to the End of the Reign of King Henry the Sixth. To which is prefixed, A Table of the Titles of all the Publick and Private Statutes during that Time, London: Mark Basket for the Crown, pp. 22|volume= has extra text (help). (in English) & (in Latin) & (in Norman)
^ abRuffhead, Owen, ed. (1763a), The Statutes at Large, Vol. I: From Magna Charta to the End of the Reign of King Henry the Sixth. To which is prefixed, A Table of the Titles of all the Publick and Private Statutes during that Time, London: Mark Basket for the Crown, pp. 148-149|volume= has extra text (help). (in English) & (in Latin) & (in Norman)
^Statutes of the Realm, Vol. I, London: G. Eyre & A. Strahan, 1810, p. 204 |volume= has extra text (help)
^Per the 1810 Statutes of the Realm, which differs in several particulars from the original Latin text, following Norman French copies or new emendations (shown in brackets). For a discussion of the textual changes (e.g., the Latin text described gallons of wheat) and relevant archaeological findings (e.g., that the penny during this period seems to have actually consisted of 30 Tower grains rather than 32), see the article at Sizes.com.
^Ruffhead, Owen, ed. (1765), The Statutes at Large, Vol. IX: From the Second Year of the Reign of King George the Third To the End of The Last Session of Parliament. To which is prefixed, A Table of the Titles of all the Publick and Private Statutes during that Time. With a Copious Index. And An Appendix, consisting of Obscure and Curious Acts, some of which were never before printed., London: Mark Basket for the Crown, p. 421|volume= has extra text (help)
^Pickering, Danby, ed. (1762), The Statutes at Large, Vol. II: From the Fifteenth Year of Edward III. to the Thirteenth Year of King Hen. IV. inclusive. To which is prefixed, A Table containing the Titles of all the Statutes during that Period, Cambridge: Joseph Bentham for Charles Bathurst, pp. 85-86|volume= has extra text (help). (in English) & (in Norman) & (in Latin)
^Pickering, Danby, ed. (1763d), The Statutes at Large, Vol. IV: From the First Year of King Richard III. to the Thirty-first Year of King Henry VIII. inclusive. To which is prefixed, A Table containing the Titles of all the Statutes during that Period., Cambridge: Joseph Bentham for Charles Bathurst, pp. 219-223|volume= has extra text (help). (in English) & (in Latin)
^Ruffhead, Owen, ed. (1763b), The Statutes at Large, Vol. II: From the First Year of King Edward the Fourth To the End of the Reign of Queen Elizabeth. To which is prefixed, A Table of the Titles of all the Publick and Private Statutes during that Time., London: Mark Basket for the Crown, p. 442|volume= has extra text (help)
^Pickering, Danby, ed. (1763f), The Statutes at Large, Vol. VI: From the First Year of Q. Mary, to the Thirty-fifth Year of Q. Elizabeth, inclusive. To which is prefixed, A Table containing the Titles of all the Statutes during that period., Cambridge: Joseph Bentham for Charles Bathurst, p. 96|volume= has extra text (help)
^Pickering, Danby, ed. (1763g), The Statutes at Large, Vol. VII: From the Thirty-ninth Year of Q. Elizabeth, to the Twelfth Year of K. Charles II. inclusive. To which is prefixed, A Table containing the Titles of all the Statutes during that Period., Cambridge: Joseph Bentham for Charles Bathurst, pp. 353-355|volume= has extra text (help)
^Pickering, Danby, ed. (1763h), The Statutes at Large, Vol. VIII: From the Twelfth Year of King Charles II., to the Last Year of King James II. inclusive. To which is prefixed, A Table containing the Titles of all the Statutes during that Period., Cambridge: Joseph Bentham for Charles Bathurst, pp. 287-289|volume= has extra text (help)
^Fitzgerald, Gerald Augustus Robert; et al., eds. (1871), The Statutes: Revised Edition, Vol. II: William & Mary to 10 George III. A.D. 1688--1770., London: George Edward Eyre & William Spottiswoode, pp. 719-720|volume= has extra text (help).
^Runnington, Charles, ed. (1798), The Statutes at Large, Vol. XIII or XVII: From the Thirty-fifth Year of the Reign of King George the Third, To the Thirty-eighth Year of the Reign of King George the Third, inclusive. To which is prefixed, A Table of the Titles of all the Public and Private Statutes during that Time. With a Copious Index., London: George Eyre & Andrew Strahan for the Crown, pp. 677-679|volume= has extra text (help)