![Weights and Measures office](https://upload.wikimedia.org/wikipedia/commons/a/a3/Weights_and_Measures_office.jpg)
The imperial system of units, imperial system or imperial units (also known as British Imperial
or Exchequer Standards of 1826) is the
system of units
A system of measurement is a collection of units of measurement and rules relating them to each other. Systems of measurement have historically been important, regulated and defined for the purposes of science and commerce. Systems of measurement i ...
first defined in the British
Weights and Measures Act 1824
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. T ...
and continued to be developed through a series of Weights and Measures Acts and amendments.
The imperial system developed from earlier
English units
English units are the units of measurement used in England up to 1826 (when they were replaced by Imperial units), which evolved as a combination of the Anglo-Saxon and Roman systems of units. Various standards have applied to English units at ...
as did the
related but differing system of
customary units of the United States. The imperial units replaced the
Winchester Standards, which were in effect from 1588 to 1825. The system came into official use across the
British Empire
The British Empire was composed of the dominions, colonies, protectorates, mandates, and other territories ruled or administered by the United Kingdom and its predecessor states. It began with the overseas possessions and trading posts esta ...
in 1826.
By the late 20th century, most nations of the former empire had
officially adopted the
metric system
The metric system is a system of measurement that succeeded the Decimal, decimalised system based on the metre that had been introduced in French Revolution, France in the 1790s. The historical development of these systems culminated in the d ...
as their main system of measurement, but imperial units are still used alongside metric units in the United Kingdom and in some other parts of the former empire, notably Canada.
The modern UK legislation defining the imperial system of units is given in the
Weights and Measures Act 1985
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. T ...
(as amended).
Implementation
The Weights and Measures Act of 1824 was initially scheduled to go into effect on 1 May 1825.
The Weights and Measures Act of 1825 pushed back the date to 1 January 1826. The 1824 Act allowed the continued use of pre-imperial units provided that they were customary, widely known, and clearly marked with imperial equivalents.
Apothecaries' units
Apothecaries' units are not mentioned in the acts of 1824 and 1825. At the time, apothecaries' weights and measures were regulated "in England, Wales, and
Berwick-upon-Tweed
Berwick-upon-Tweed (), sometimes known as Berwick-on-Tweed or simply Berwick, is a town and civil parish in Northumberland, England, south of the Anglo-Scottish border, and the northernmost town in England. The 2011 United Kingdom census recor ...
" by the
London College of Physicians
The Royal College of Physicians (RCP) is a British professional membership body dedicated to improving the practice of medicine, chiefly through the accreditation of physicians by examination. Founded by royal charter from King Henry VIII in 1 ...
, and in Ireland by the
Dublin College of Physicians. In Scotland, apothecaries' units were unofficially regulated by the
Edinburgh College of Physicians
The Royal College of Physicians of Edinburgh (RCPE) is a medical royal college in Scotland. It is one of three organisations that sets the specialty training standards for physicians in the United Kingdom. It was established by Royal charter ...
. The three colleges published, at infrequent intervals,
pharmacopoeia
A pharmacopoeia, pharmacopeia, or pharmacopoea (from the obsolete typography ''pharmacopœia'', meaning "drug-making"), in its modern technical sense, is a book containing directions for the identification of compound medicines, and published by ...
s, the London and Dublin editions having the force of law.
Imperial apothecaries' measures, based on the imperial pint of 20 fluid ounces, were introduced by the publication of the London Pharmacopoeia of 1836,
the Edinburgh Pharmacopoeia of 1839,
and the Dublin Pharmacopoeia of 1850.
The Medical Act of 1858 transferred to
The Crown
The Crown is the state in all its aspects within the jurisprudence of the Commonwealth realms and their subdivisions (such as the Crown Dependencies, overseas territories, provinces, or states). Legally ill-defined, the term has different ...
the right to publish the official pharmacopoeia and to regulate apothecaries' weights and measures.
Units
Length
Metric equivalents in this article usually assume the latest official definition. Before this date, the most precise measurement of the imperial Standard Yard was metres.
Area
Volume
The
Weights and Measures Act 1824
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. T ...
invalidated the various different gallons in use in the British Empire, declaring them to be replaced by the
statute
A statute is a formal written enactment of a legislative authority that governs the legal entities of a city, state, or country by way of consent. Typically, statutes command or prohibit something, or declare policy. Statutes are rules made by le ...
gallon (which became known as the imperial gallon), a unit close in volume to the
ale gallon
The gallon is a unit of volume in imperial units and United States customary units. Three different versions are in current use:
*the imperial gallon (imp gal), defined as , which is or was used in the United Kingdom, Ireland, Canada, Austr ...
. The 1824 Act defined as the volume of a gallon to be that of of distilled water weighed in air with brass weights with the barometer standing at at a temperature of .
[. (The date of coming into effect was 1 May 1825).] The 1824 Act went on to give this volume as .
The
Weights and Measures Act 1963
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. T ...
refined this definition to be the volume of 10 pounds of distilled water of density weighed in air of density against weights of density , which works out to .
[10 pounds = 4535.9237 grams. @ 0.998859 g/mL => 4546.092 mL] The
Weights and Measures Act 1985
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. T ...
defined a gallon to be exactly (approximately ).
British apothecaries' volume measures
These measurements were in use from 1826, when the new imperial gallon was defined. For pharmaceutical purposes, they were replaced by the metric system in the United Kingdom on 1 January 1971. In the US, though no longer recommended, the
apothecaries' system
The apothecaries' system, or apothecaries' weights and measures, is a historical system of mass and volume units that were used by physicians and apothecaries for medical prescriptions and also sometimes by scientists."Medicinal-Gewicht, Apotheke ...
is still used occasionally in medicine, especially in
prescriptions for older medications.
Mass and weight
In the 19th and 20th centuries, the UK used three different systems for mass and weight.
*
troy weight
Troy weight is a system of Physical unit, units of mass that originated in 15th-century England, and is primarily used in the precious metals industry. The troy weight units are the Grain (unit), grain, the pennyweight (24 grains), the troy oun ...
, used for precious metals;
*
avoirdupois
The avoirdupois system (; abbreviated avdp.) is a measurement system of weights that uses pounds and ounces as units. It was first commonly used in the 13th century AD and was updated in 1959.
In 1959, by international agreement, the definiti ...
weight, used for most other purposes; and
*
apothecaries' weight
The apothecaries' system, or apothecaries' weights and measures, is a historical system of mass and volume units that were used by physicians and apothecaries for medical prescriptions and also sometimes by scientists."Medicinal-Gewicht, Apotheke ...
, now virtually unused since the metric system is used for all scientific purposes.
The distinction between
mass and weight is not always clearly drawn. Strictly a pound is a unit of mass, but it is commonly referred to as a weight. When a distinction is necessary, the term ''
pound-force
The pound of force or pound-force (symbol: lbf, sometimes lbf,) is a unit of force used in some systems of measurement, including English Engineering units and the foot–pound–second system.
Pound-force should not be confused with pound-ma ...
'' may refer to a unit of force rather than mass. The troy pound () was made the primary unit of mass by the 1824 Act and its use was abolished in the UK on 1 January 1879,
with only the troy ounce () and its
decimal
The decimal numeral system (also called the base-ten positional numeral system and denary or decanary) is the standard system for denoting integer and non-integer numbers. It is the extension to non-integer numbers of the Hindu–Arabic numeral ...
subdivisions retained.
The ''Weights and Measures Act 1855'' (18 & 19 Victoria C72) made the avoirdupois pound the primary unit of mass.
In all the systems, the fundamental unit is the
pound
Pound or Pounds may refer to:
Units
* Pound (currency), a unit of currency
* Pound sterling, the official currency of the United Kingdom
* Pound (mass), a unit of mass
* Pound (force), a unit of force
* Rail pound, in rail profile
Symbols
* Po ...
, and all other units are defined as fractions or multiples of it.
Natural equivalents
The 1824 Act of Parliament defined the yard and pound by reference to the
prototype
A prototype is an early sample, model, or release of a product built to test a concept or process. It is a term used in a variety of contexts, including semantics, design, electronics, and Software prototyping, software programming. A prototyp ...
standards, and it also defined the values of certain
physical constants
A physical constant, sometimes fundamental physical constant or universal constant, is a physical quantity that is generally believed to be both universal in nature and have constant value in time. It is contrasted with a mathematical constant, ...
, to make provision for re-creation of the standards if they were to be damaged. For the yard, the length of a
pendulum
A pendulum is a weight suspended from a pivot so that it can swing freely. When a pendulum is displaced sideways from its resting, equilibrium position, it is subject to a restoring force due to gravity that will accelerate it back toward the ...
beating
second
The second (symbol: s) is the unit of time in the International System of Units (SI), historically defined as of a day – this factor derived from the division of the day first into 24 hours, then to 60 minutes and finally to 60 seconds ...
s at the latitude of Greenwich at
Mean Sea Level
There are several kinds of mean in mathematics
Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. ...
''in vacuo'' was defined as inches. For the pound, the mass of a cubic inch of distilled water at an
atmospheric pressure
Atmospheric pressure, also known as barometric pressure (after the barometer), is the pressure within the atmosphere of Earth. The standard atmosphere (symbol: atm) is a unit of pressure defined as , which is equivalent to 1013.25 millibars, 7 ...
of 30
inches of mercury
Inch of mercury (inHg and ″Hg) is a non- SI unit of measurement for pressure. It is used for barometric pressure in weather reports, refrigeration and aviation in the United States.
It is the pressure exerted by a column of mercury in heigh ...
and a temperature of 62°
Fahrenheit
The Fahrenheit scale () is a temperature scale based on one proposed in 1724 by the physicist Daniel Gabriel Fahrenheit (1686–1736). It uses the degree Fahrenheit (symbol: °F) as the unit. Several accounts of how he originally defined his ...
was defined as 252.458 grains, with there being 7,000 grains per pound.
Following the destruction of the original prototypes in the
1834 Houses of Parliament fire, it proved impossible to recreate the standards from these definitions, and a new
Weights and Measures Act
A weights and measures act is a kind of legislative act found in many jurisdictions establishing technical standards for weights and measures.
Notable acts of this type include:
* Various Weights and Measures Acts (UK) or the various legislative ...
(18 & 19 Victoria. Cap. 72) was passed in 1855 which permitted the recreation of the prototypes from recognized
secondary standards.
Current use
United Kingdom
![Metric_and_imperial_systems_(2019)](https://upload.wikimedia.org/wikipedia/commons/0/08/Metric_and_imperial_systems_%282019%29.svg)
Since the
Weights and Measures Act 1985
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. T ...
, British law defines base imperial units in terms of their metric equivalent. The metric system is routinely used in business and technology within the United Kingdom, with imperial units remaining in widespread use amongst the public.
All UK roads use the imperial system except for weight limits, and newer height or width restriction signs give metric alongside imperial.
![MetricImperialUSCustomaryUnits](https://upload.wikimedia.org/wikipedia/commons/0/00/MetricImperialUSCustomaryUnits.jpg)
Traders in the UK may accept requests from customers specified in imperial units, and scales which display in both unit systems are commonplace in the retail trade. Metric price signs may be accompanied by imperial price signs provided that the imperial signs are no larger and no more prominent than the metric ones.
The United Kingdom completed its official partial transition to the metric system in 1995, with imperial units still legally mandated for certain applications such as draught beer and cider,
and road-signs.
Therefore, the speedometers on vehicles sold in the UK must be capable of displaying miles per hour. Even though the
troy pound
Troy weight is a system of units of mass that originated in 15th-century England, and is primarily used in the precious metals industry. The troy weight units are the grain, the pennyweight (24 grains), the troy ounce (20 pennyweights), and the ...
was outlawed in the UK in the Weights and Measures Act of 1878, the ''troy ounce'' ''may'' still be used for the weights of precious stones and metals. The original railways (many built in the Victorian era) are a big user of imperial units, with distances officially measured in miles and yards or miles and
chains
A chain is a serial assembly of connected pieces, called links, typically made of metal, with an overall character similar to that of a rope in that it is flexible and curved in compression but linear, rigid, and load-bearing in tension. A c ...
, and also feet and inches, and speeds are in miles per hour.
Some British people still use one or more imperial units in everyday life for distance (miles, yards, feet, and inches) and some types of volume measurement (especially milk and beer in pints; rarely for canned or bottled soft drinks, or
petrol
Gasoline (; ) or petrol (; ) (see ) is a transparent, petroleum-derived flammable liquid that is used primarily as a fuel in most spark-ignited internal combustion engines (also known as petrol engines). It consists mostly of organic co ...
).
, many British people also still use imperial units in everyday life for body weight (stones and pounds for adults, pounds and ounces for babies). Government documents aimed at the public may give body weight and height in imperial units as well as in metric. A survey in 2015 found that many people did not know their body weight or height in both systems. People under the age of 40 preferred the metric system but people aged 40 and over preferred the imperial system. As in other English-speaking countries, including
Australia
Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...
,
Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...
and the
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...
, the height of horses is usually measured in
hands
A hand is a prehensile, multi-fingered appendage located at the end of the forearm or forelimb of primates such as humans, chimpanzees, monkeys, and lemurs. A few other vertebrates such as the koala (which has two opposable thumbs on each " ...
, standardised to . Fuel consumption for vehicles is commonly stated in miles per gallon (mpg), though official figures always include litres per equivalents and fuel is sold in litres. When sold
draught in licensed premises, beer and cider must be sold in pints, half-pints or third-pints. Cow's milk is available in both litre- and pint-based containers in supermarkets and shops. Areas of land associated with farming, forestry and real estate are commonly advertised in acres and square feet but, for contracts and
land registration
Land registration is any of various systems by which matters concerning ownership, possession, or other rights in land are formally recorded (usually with a government agency or department) to provide evidence of title, facilitate transactions, a ...
purposes, the units are always hectares and square metres.
[ See paragraph 7.4.]
Office space and industrial units are usually advertised in square feet. Steel pipe sizes are sold in increments of inches, while copper pipe is sold in increments of millimetres. Road bicycles have their frames measured in centimetres, while off-road bicycles have their frames measured in inches.
Display size
On 2D displays, such as computer monitors and TVs, the display size (or viewable image size or VIS) is the physical size of the area where pictures and videos are displayed. The size of a screen is usually described by the length of its diago ...
s for screens on television sets and computer monitors are always
diagonal
In geometry, a diagonal is a line segment joining two vertices of a polygon or polyhedron, when those vertices are not on the same edge. Informally, any sloping line is called diagonal. The word ''diagonal'' derives from the ancient Greek δ ...
ly measured in inches. Food sold by length or width, e.g. pizzas or sandwiches, is generally sold in inches. Clothing is usually sized in inches, with the metric equivalent often shown as a small supplementary indicator. Gas is usually measured by the cubic foot or cubic metre, but is billed like electricity by the
kilowatt hour
A kilowatt-hour (unit symbol: kW⋅h or kW h; commonly written as kWh) is a unit of energy: one kilowatt of power for one hour. In terms of SI derived units with special names, it equals 3.6 megajoules (MJ). Kilowatt-hours are a common bil ...
.
Pre-packaged products can show both metric and imperial measures, and it is also common to see imperial pack sizes with metric only labels, e.g. a tin of Lyle's Golden Syrup is always labelled with no imperial indicator. Similarly most jars of jam and packs of sausages are labelled with no imperial indicator.
India
India
India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...
began converting to the metric system from the imperial system between 1955 and 1962. The metric system in weights and measures was adopted by the
Indian Parliament
The Parliament of India ( IAST: ) is the supreme legislative body of the Republic of India. It is a bicameral legislature composed of the president of India and two houses: the Rajya Sabha (Council of States) and the Lok Sabha (House of the ...
in December 1956 with the ''Standards of Weights and Measures Act'', which took effect beginning 1 October 1958. By 1962, metric units became "mandatory and exclusive."
Today all official measurements are made in the metric system. In common usage some older Indians may still refer to imperial units. Some measurements, such as the heights of mountains, are still recorded in feet. Tyre rim diameters are still measured in inches, as used worldwide. Industries like the construction and the real estate industry still use both the metric and the imperial system though it is more common for sizes of homes to be given in square feet and land in acres.
[Acharya, Anil Kumar. ''History of Decimalisation Movement in India'', Auto-Print & Publicity House, 1958.]
In
Standard Indian English
Indian English has developed a number of dialects, distinct from the General/Standard Indian English that educators have attempted to establish and institutionalise, and it is possible to distinguish a person's sociolinguistic background from th ...
, as in
Australian
Australian(s) may refer to:
Australia
* Australia, a country
* Australians, citizens of the Commonwealth of Australia
** European Australians
** Anglo-Celtic Australians, Australians descended principally from British colonists
** Aboriginal Au ...
,
Singaporean
Singaporeans, or the Singaporean people, refers to citizens or people who identify with the sovereign island city-state of Singapore. Singapore is a multi-ethnic, multi-cultural and multi-lingual country. Singaporeans of Chinese, Malay, India ...
, and
British English
British English (BrE, en-GB, or BE) is, according to Lexico, Oxford Dictionaries, "English language, English as used in Great Britain, as distinct from that used elsewhere". More narrowly, it can refer specifically to the English language in ...
, metric units such as the litre, metre, and
tonne
The tonne ( or ; symbol: t) is a unit of mass equal to 1000 kilograms. It is a non-SI unit accepted for use with SI. It is also referred to as a metric ton to distinguish it from the non-metric units of the short ton ( United State ...
utilise the traditional spellings brought over from
French
French (french: français(e), link=no) may refer to:
* Something of, from, or related to France
** French language, which originated in France, and its various dialects and accents
** French people, a nation and ethnic group identified with Franc ...
, which differ from those used in the
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...
and the
Philippines
The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no),
* bik, Republika kan Filipinas
* ceb, Republika sa Pilipinas
* cbk, República de Filipinas
* hil, Republ ...
. The imperial long ton is invariably spelt with one 'n'.
Hong Kong
Hong Kong
Hong Kong ( (US) or (UK); , ), officially the Hong Kong Special Administrative Region of the People's Republic of China ( abbr. Hong Kong SAR or HKSAR), is a city and special administrative region of China on the eastern Pearl River Delt ...
has three main systems of
units of measurement
A unit of measurement is a definite magnitude (mathematics), magnitude of a quantity, defined and adopted by convention or by law, that is used as a standard for measurement of the same kind of quantity. Any other quantity of that kind can ...
in current use:
* The
Chinese units of measurement
Chinese units of measurement, known in Chinese as the ''shìzhì'' ("market system"), are the traditional units of measurement of the Han Chinese. Although Chinese numerals have been decimal (base-10) since the Shang dynasty, Shang, several Chine ...
of the
Qing Empire
The Qing dynasty ( ), officially the Great Qing,, was a Manchu-led imperial dynasty of China and the last orthodox dynasty in Chinese history. It emerged from the Later Jin dynasty founded by the Jianzhou Jurchens, a Tungusic-speak ...
(no longer in widespread use in China);
* British imperial units; and
* The
metric system
The metric system is a system of measurement that succeeded the Decimal, decimalised system based on the metre that had been introduced in French Revolution, France in the 1790s. The historical development of these systems culminated in the d ...
.
In 1976 the
Hong Kong Government
The Government of the Hong Kong Special Administrative Region, commonly known as the Hong Kong Government or HKSAR Government, refers to the Executive (government), executive authorities of Hong Kong Special administrative regions of China, ...
started the conversion to the metric system, and as of 2012 measurements for government purposes, such as road signs, are almost always in metric units. All three systems are officially permitted for trade,
and in the wider society a mixture of all three systems prevails.
The Chinese system's most commonly used units for length are (''lei
5''), (''zoeng
6''), (''
cek3''), (''
cyun3''), (''fan
1'') in descending scale order. These units are now rarely used in daily life, the imperial and metric systems being preferred. The imperial equivalents are written with the same basic Chinese characters as the Chinese system. In order to distinguish between the units of the two systems, the units can be prefixed with "Ying" (, ''jing
1'') for the imperial system and "Wa" (, ''waa
4'') for the Chinese system. In writing, derived characters are often used, with an additional (mouth)
radical
Radical may refer to:
Politics and ideology Politics
*Radical politics, the political intent of fundamental societal change
*Radicalism (historical), the Radical Movement that began in late 18th century Britain and spread to continental Europe and ...
to the left of the original Chinese character, for writing imperial units. The most commonly used units are the
mile
The mile, sometimes the international mile or statute mile to distinguish it from other miles, is a British imperial unit and United States customary unit of distance; both are based on the older English unit of length equal to 5,280 English ...
or "li" (, ''li
1''), the
yard
The yard (symbol: yd) is an English unit of length in both the British imperial and US customary systems of measurement equalling 3 feet or 36 inches. Since 1959 it has been by international agreement standardized as exactly 0.914 ...
or "ma" (, ''maa
5''), the
foot
The foot ( : feet) is an anatomical structure found in many vertebrates. It is the terminal portion of a limb which bears weight and allows locomotion. In many animals with feet, the foot is a separate organ at the terminal part of the leg made ...
or "chek" (, ''cek
3''), and the
inch
Measuring tape with inches
The inch (symbol: in or ″) is a unit of length in the British imperial and the United States customary systems of measurement. It is equal to yard or of a foot. Derived from the Roman uncia ("twelfth") ...
or "tsun" (, ''cyun
3'').
The traditional measure of flat area is the square foot (, ''fong
1 cek
3, ping
4 fong
1 cek
3'') of the imperial system, which is still in common use for real estate purposes. The measurement of agricultural plots and fields is traditionally conducted in (''mau
5'') of the Chinese system.
For the measurement of volume, Hong Kong officially uses the metric system, though the gallon (, ''gaa
1 leon
4-2'') is also occasionally used.
Canada
![Canadian canned food labels showing imperial and metric units of measurement](https://upload.wikimedia.org/wikipedia/commons/e/e2/Canadian_canned_food_labels_showing_imperial_and_metric_units_of_measurement.jpg)
During the 1970s, the metric system and SI units were introduced in Canada to replace the imperial system. Within the government, efforts to implement the metric system were extensive; almost any agency, institution, or function provided by the government uses SI units exclusively. Imperial units were eliminated from all public road signs and both systems of measurement will still be found on privately owned signs, such as the height warnings at the entrance of a
parkade
A multistorey car park (British and Singapore English) or parking garage (American English), also called a multistory, parking building, parking structure, parkade (mainly Canadian), parking ramp, parking deck or indoor parking, is a build ...
. In the 1980s, momentum to fully convert to the metric system stalled when the government of
Brian Mulroney
Martin Brian Mulroney ( ; born March 20, 1939) is a Canadian lawyer, businessman, and politician who served as the 18th prime minister of Canada from 1984 to 1993.
Born in the eastern Quebec city of Baie-Comeau, Mulroney studied political sci ...
was elected. There was heavy opposition to metrication and as a compromise the government maintains legal definitions for and allows use of imperial units as long as metric units are shown as well.
The law requires that measured products (such as fuel and meat) be priced in metric units and an imperial price can be shown if a metric price is present.
[
][
] There tends to be leniency in regards to fruits and vegetables being priced in imperial units only.
Environment Canada
Environment and Climate Change Canada (ECCC; french: Environnement et Changement climatique Canada),Environment and Climate Change Canada is the applied title under the Federal Identity Program; the legal title is Department of the Environment ( ...
still offers an imperial unit option beside metric units, even though weather is typically measured and reported in metric units in the Canadian media. Some radio stations near the United States border (such as
CIMX
CIMX-FM (88.7 MHz, ''Pure Country 89'') is a commercial radio station in Windsor, Ontario, Canada. It primarily serves Essex County, but has a signal that reaches the entire Detroit-Windsor metropolitan area. It is owned by Bell Media and airs a ...
and
CIDR
Classless Inter-Domain Routing (CIDR ) is a method for allocating IP addresses and for IP routing. The Internet Engineering Task Force introduced CIDR in 1993 to replace the previous classful network addressing architecture on the Internet. Its g ...
) primarily use imperial units to report the weather. Railways in Canada also continue to use imperial units.
Imperial units are still used in ordinary conversation. Today, Canadians typically use a mix of metric and imperial measurements in their daily lives. The use of the metric and imperial systems varies by age. The older generation mostly uses the imperial system, while the younger generation more often uses the metric system.
Quebec
Quebec ( ; )According to the Canadian government, ''Québec'' (with the acute accent) is the official name in Canadian French and ''Quebec'' (without the accent) is the province's official name in Canadian English is one of the thirtee ...
has implemented metrication more fully. Newborns are measured in SI at hospitals, but the birth weight and length is also announced to family and friends in imperial units. Drivers' licences use SI units, though many English-speaking Canadians give their height and weight in imperial. In livestock auction markets, cattle are sold in dollars per
hundredweight
The hundredweight (abbreviation: cwt), formerly also known as the centum weight or quintal, is a British imperial and US customary unit of weight or mass. Its value differs between the US and British imperial systems. The two values are distingu ...
(short), whereas hogs are sold in dollars per hundred kilograms. Imperial units still dominate in recipes, construction, house renovation and gardening. Land is now surveyed and registered in metric units whilst initial surveys used imperial units. For example, partitioning of farm land on the prairies in the late 19th and early 20th centuries was done in imperial units; this accounts for imperial units of distance and area retaining wide use in the
Prairie Provinces
The Canadian Prairies (usually referred to as simply the Prairies in Canada) is a region in Western Canada. It includes the Canadian portion of the Great Plains and the Prairie Provinces, namely Alberta, Saskatchewan, and Manitoba. These provin ...
. In English-speaking Canada commercial and residential spaces are mostly (but not exclusively) constructed using square feet, while in French-speaking Quebec commercial and residential spaces are constructed in metres and advertised using both square metres and square feet as equivalents. Carpet or flooring tile is purchased by the square foot, but less frequently also in square metres. Motor-vehicle fuel consumption is reported in both litres per and statute miles per imperial gallon, leading to the erroneous impression that Canadian vehicles are 20% more fuel-efficient than their apparently identical American counterparts for which fuel economy is reported in statute miles per US gallon (neither country specifies which gallon is used). Canadian railways maintain exclusive use of imperial measurements to describe train length (feet), train height (feet), capacity (
tons), speed (mph), and trackage (miles).
Imperial units also retain common use in firearms and ammunition. Imperial measures are still used in the description of cartridge types, even when the cartridge is of relatively recent invention (e.g.,
.204 Ruger
The .204 Ruger is a centerfire rifle cartridge developed by Hornady and Ruger. At the time of its introduction in 2004, the .204 Ruger was the second-highest velocity commercially produced ammunition and the only centerfire cartridge produc ...
,
.17 HMR
.17 Hornady Magnum Rimfire, commonly known as the .17 HMR, is a rimfire rifle cartridge developed by Hornady in 2002. It was developed by necking down a .22 Magnum case to take a .17 caliber (4.5 mm) projectile. Commonly loaded with a 1 ...
, where the calibre is expressed in decimal fractions of an inch). Ammunition that is already classified in metric is still kept metric (e.g.,
9×19mm). In the manufacture of ammunition, bullet and powder weights are expressed in terms of
grains
A grain is a small, hard, dry fruit (caryopsis) – with or without an attached hull layer – harvested for human or animal consumption. A grain crop is a grain-producing plant. The two main types of commercial grain crops are cereals and legume ...
for both metric and imperial cartridges.
As in most of the western world, air navigation is based on ''nautical'' units, e.g., the nautical mile, which is neither imperial nor metric, though altitude is still measured in imperial feet in keeping with the international standard.
Australia
While Metrication in Australia has largely ended the official use of imperial units, for particular measurements, international use of imperial units is still followed.
* In licensed venues, draught beer and cider is sold in glasses and jugs with
sizes
Size in general is the magnitude or dimensions of a thing. More specifically, ''geometrical size'' (or ''spatial size'') can refer to linear dimensions (length, width, height, diameter, perimeter), area, or volume. Size can also be measu ...
based on the imperial fluid ounce, though rounded to the nearest 5 mL.
* Newborns are measured in metric at hospitals, but the birth weight and length is sometimes also announced to family and friends in imperial units.
* Screen sizes, are frequently advertised in inches instead of or as well as centimetres.
* Property size is frequently advertised in acres, but is mostly as square metres.
* Navigation is done in nautical miles, and water-based speed limits are in nautical miles per hour.
* Historical writing and presentations may include pre-metric units to reflect the context of the era represented.
* The illicit drug trade in Australia still often uses imperial measurements, particularly when dealing with smaller amounts closer to end user levels e.g. "8-ball" an 8th of an ounce or ; cannabis is often traded in ounces ("oz") and pounds ("p")
* Firearm barrel length are almost always referred by in inches, ammunition is also still measured in grain and ounces as well as grams.
As a result of cultural transmission of British and American English in Australia, there has also been noted to be a cause for residual use of imperial units of measure.
New Zealand
New Zealand introduced the metric system on 15 December 1976. Aviation was exempt, with altitude and airport elevation continuing to be measured in feet whilst navigation is done in
nautical mile
A nautical mile is a unit of length used in air, marine, and space navigation, and for the definition of territorial waters. Historically, it was defined as the meridian arc length corresponding to one minute ( of a degree) of latitude. Today ...
s; all other aspects (fuel quantity, aircraft weight, runway length, etc.) use metric units.
Screen sizes for devices such as televisions, monitors and phones, and wheel rim sizes for vehicles, are stated in inches, as is the convention in the rest of the world - and a 1992 study found a continued use of imperial units for birth weight and human height alongside metric units.
Ireland
Ireland has officially changed over to the metric system since entering the
European Union
The European Union (EU) is a supranational political and economic union of member states that are located primarily in Europe. The union has a total area of and an estimated total population of about 447million. The EU has often been des ...
, with distances on new road signs being metric since 1997 and speed limits being metric since 2005. The imperial system remains in limited use – for sales of beer in pubs (traditionally sold by the pint). All other goods are required by law to be sold in metric units with traditional quantities being retained for goods like butter and sausages, which are sold in packaging. The majority of cars sold pre-2005 feature speedometers with miles per hour as the primary unit, but with a kilometres per hour display. Often signs such as those for bridge height can display both metric and imperial units. Imperial measurements continue to be used colloquially by the general population especially with height and distance measurements such as feet, inches, and acres as well as for weight with pounds and stones still in common use among people of all ages. Measurements such as yards have fallen out of favour with younger generations. Ireland's railways still use imperial measurements for distances and speed signage. Property is usually listed in square feet as well as metres also.
Horse racing in Ireland still continues to use stones, pounds, miles and furlongs as measurements.
Bahamas
Imperial measurements remain in general use in the
Bahamas
The Bahamas (), officially the Commonwealth of The Bahamas, is an island country within the Lucayan Archipelago of the West Indies in the Atlantic Ocean, North Atlantic. It takes up 97% of the Lucayan Archipelago's land area and is home to ...
.
Legally, both the imperial and metric systems are recognised by the Weights and Measures Act 2006.
Other countries
Some imperial measurements remain in limited use in
Malaysia
Malaysia ( ; ) is a country in Southeast Asia. The federation, federal constitutional monarchy consists of States and federal territories of Malaysia, thirteen states and three federal territories, separated by the South China Sea into two r ...
, the
Philippines
The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no),
* bik, Republika kan Filipinas
* ceb, Republika sa Pilipinas
* cbk, República de Filipinas
* hil, Republ ...
,
Sri Lanka
Sri Lanka (, ; si, ශ්රී ලංකා, Śrī Laṅkā, translit-std=ISO (); ta, இலங்கை, Ilaṅkai, translit-std=ISO ()), formerly known as Ceylon and officially the Democratic Socialist Republic of Sri Lanka, is an ...
and
South Africa
South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...
. Measurements in feet and inches, especially for a person's height, are frequently encountered in conversation and non-governmental publications.
Prior to metrication, it was a common practice in Malaysia for people to refer to unnamed locations and small settlements along major roads by referring to how many miles the said locations were from the nearest major town. In some cases, these eventually became the official names of the locations; in other cases, such names have been largely or completely superseded by new names. An example of the former is Batu 32 (literally "Mile 32" in
Malay
Malay may refer to:
Languages
* Malay language or Bahasa Melayu, a major Austronesian language spoken in Indonesia, Malaysia, Brunei and Singapore
** History of the Malay language, the Malay language from the 4th to the 14th century
** Indonesi ...
), which refers to the area surrounding the intersection between
Federal Route 22 (the
Tamparuli
Tamparuli is a small town and a sub-district of Tuaran on the west coast of Sabah, Malaysia. It is populated mainly by native Dusuns, while a sizeable Chinese community (of whom most are Hakkas) runs most of the shops in the town proper. As with ...
-
Sandakan
Sandakan (, Jawi: , ) formerly known at various times as Elopura, is the capital of the Sandakan District in Sabah, Malaysia. It is the second largest city in Sabah after Kota Kinabalu. It is located on the Sandakan Peninsula and east coast of ...
highway) and
Federal Route 13 (the Sandakan-
Tawau
Tawau (, Jawi: , ), formerly known as Tawao, is the capital of the Tawau District in Sabah, Malaysia. It is the third-largest city in Sabah, after Kota Kinabalu and Sandakan. It is located on the Semporna Peninsula in the southeast coast of t ...
highway). The area is so named because it is 32 miles west of Sandakan, the nearest major town.
Petrol is still sold by the imperial gallon in
Anguilla
Anguilla ( ) is a British Overseas Territory in the Caribbean. It is one of the most northerly of the Leeward Islands in the Lesser Antilles, lying east of Puerto Rico and the Virgin Islands and directly north of Saint Martin. The territo ...
,
Antigua and Barbuda
Antigua and Barbuda (, ) is a sovereign country in the West Indies. It lies at the juncture of the Caribbean Sea and the Atlantic Ocean in the Leeward Islands part of the Lesser Antilles, at 17°N latitude. The country consists of two maj ...
,
Belize
Belize (; bzj, Bileez) is a Caribbean and Central American country on the northeastern coast of Central America. It is bordered by Mexico to the north, the Caribbean Sea to the east, and Guatemala to the west and south. It also shares a wate ...
,
Myanmar
Myanmar, ; UK pronunciations: US pronunciations incl. . Note: Wikipedia's IPA conventions require indicating /r/ even in British English although only some British English speakers pronounce r at the end of syllables. As John C. Wells, Joh ...
, the
Cayman Islands
The Cayman Islands () is a self-governing British Overseas Territory—the largest by population in the western Caribbean Sea. The territory comprises the three islands of Grand Cayman, Cayman Brac and Little Cayman, which are located to the ...
,
Dominica
Dominica ( or ; Kalinago: ; french: Dominique; Dominican Creole French: ), officially the Commonwealth of Dominica, is an island country in the Caribbean. The capital, Roseau, is located on the western side of the island. It is geographically ...
,
Grenada
Grenada ( ; Grenadian Creole French: ) is an island country in the West Indies in the Caribbean Sea at the southern end of the Grenadines island chain. Grenada consists of the island of Grenada itself, two smaller islands, Carriacou and Pe ...
,
Montserrat
Montserrat ( ) is a British Overseas Territories, British Overseas Territory in the Caribbean. It is part of the Leeward Islands, the northern portion of the Lesser Antilles chain of the West Indies. Montserrat is about long and wide, with r ...
,
St Kitts and Nevis
Saint Kitts and Nevis (), officially the Federation of Saint Christopher and Nevis, is an island country and microstate consisting of the two islands of Saint Kitts and Nevis, both located in the West Indies, in the Leeward Islands chain of ...
and
St. Vincent and the Grenadines
Saint Vincent and the Grenadines () is an island country in the Caribbean. It is located in the southeast Windward Islands of the Lesser Antilles, which lie in the West Indies at the southern end of the eastern border of the Caribbean Sea wh ...
. The
United Arab Emirates
The United Arab Emirates (UAE; ar, اَلْإِمَارَات الْعَرَبِيَة الْمُتَحِدَة ), or simply the Emirates ( ar, الِْإمَارَات ), is a country in Western Asia (The Middle East). It is located at th ...
Cabinet in 2009 issued the Decree No. (270 / 3) specifying that, from 1 January 2010, the new unit sale price for petrol will be the litre and not the gallon, which was in line with the UAE Cabinet Decision No. 31 of 2006 on the national system of measurement, which mandates the use of International System of units as a basis for the legal units of measurement in the country.
Sierra Leone switched to selling fuel by the litre in May 2011.
In October 2011, the Antigua and Barbuda government announced the re-launch of the Metrication Programme in accordance with the Metrology Act 2007, which established the International System of Units as the legal system of units. The Antigua and Barbuda government has committed to a full conversion from the imperial system by the first quarter of 2015.
See also
Explanatory notes
Citations
General sources
* Appendices B and C o
NIST Handbook 44* Also available as
PDF file
* 6 George IV chapter 12, 1825 (statute)
External links
Canada Weights and Measures Act 1970-71-72General table of units of measure – NIST – pdfHow Many? A Dictionary of Units of Measurement
*
{{systems of measurement
Imperial units
Customary units of measurement
Systems of units
1824 introductions