|Unit system||imperial/US units|
|Symbol||in or ″ (the double prime)|
|1 in in ...||... is equal to ...|
|imperial/US units|| 1/ yd |
|metric (SI) units||25.4 mm|
The inch (abbreviation: in or ″ ) is a unit of length in the (British) imperial and United States customary systems of measurement. It is equal to 1⁄36 yard or 1⁄12 of a foot. Derived from the Roman uncia ("twelfth"), the word inch is also sometimes used to translate similar units in other measurement systems, usually understood as deriving from the width of the human thumb.
The prime symbol, double prime symbol, triple prime symbol, quadruple prime symbol etc., are used to designate units and for other purposes in mathematics, the sciences, linguistics and music.
Length is a measure of distance. In the International System of Quantities, length is any quantity with dimension distance. In most systems of measurement, the unit of length is a base unit, from which other units are derived.
The system of imperial units or the imperial system is the system of units first defined in the British Weights and Measures Act of 1824, which was later refined and reduced. 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. By the late 20th century, most nations of the former empire had officially adopted the metric system as their main system of measurement, although some imperial units are still used in the United Kingdom, Canada and other countries formerly part of the British Empire. The imperial system developed from what were first known as English units, as did the related system of United States customary units.
Standards for the exact length of an inch have varied in the past, but since the adoption of the international yard during the 1950s and 1960s it has been based on the metric system and defined as exactly 25.4 mm.
The metric system is an internationally recognised decimalised system of measurement. It is in widespread use, and where it is adopted, it is the only or most common system of weights and measures. It is now known as the International System of Units (SI). It is used to measure everyday things such as the mass of a sack of flour, the height of a person, the speed of a car, and the volume of fuel in its tank. It is also used in science, industry and trade.
The millimetre or millimeter is a unit of length in the metric system, equal to one thousandth of a metre, which is the SI base unit of length. Therefore, there are one thousand millimetres in a metre. There are ten millimetres in a centimetre.
The English word "inch" (Old English :ynce) was an early borrowing from Latin uncia ("one-twelfth; Roman inch; Roman ounce") not present in other Germanic languages. The vowel change from Latin /u/ to Old English /y/ (which became Modern English /ɪ/) is known as umlaut. The consonant change from the Latin /k/ (spelled c) to English /tʃ/ is palatalisation. Both were features of Old English phonology; see Phonological history of Old English § Palatalization and Germanic umlaut § I-mutation in Old English for more information.
Latin is a classical language belonging to the Italic branch of the Indo-European languages. The Latin alphabet is derived from the Etruscan and Greek alphabets and ultimately from the Phoenician alphabet.
The Germanic languages are a branch of the Indo-European language family spoken natively by a population of about 515 million people mainly in Europe, North America, Oceania and Southern Africa.
The Germanic umlaut is a type of linguistic umlaut in which a back vowel changes to the associated front vowel (fronting) or a front vowel becomes closer to (raising) when the following syllable contains, , or. It took place separately in various Germanic languages starting around AD 450 or 500 and affected all of the early languages except Gothic. An example of the resulting vowel alternation is the English plural foot ~ feet.
"Inch" is cognate with "ounce" (Old English :ynse), whose separate pronunciation and spelling reflect its reborrowing in Middle English from Anglo-Norman unce and ounce.
The ounce is a unit of mass, weight, or volume used in most British derived customary systems of measurement. The common avoirdupois ounce is 1⁄16 of a common avoirdupois pound; this is the United States customary and British imperial ounce. It is primarily used in the United States to measure packaged foods and food portions, postal items, areal density of fabric and paper, boxing gloves, and so on; but sometimes also elsewhere in the Anglosphere.
Middle English was a form of the English language spoken after the Norman conquest (1066) until the late 15th century. English underwent distinct variations and developments following the Old English period. Scholarly opinion varies, but the Oxford English Dictionary specifies the period when Middle English was spoken as being from 1150 to 1500. This stage of the development of the English language roughly followed the High to the Late Middle Ages.
Anglo-Norman, also known as Anglo-Norman French, was a dialect of French that was used in England and, to a lesser extent, elsewhere in the British Isles during the Anglo-Norman period.
In many other European languages, the word for "inch" is the same as or derived from the word for "thumb", as a man's thumb is about an inch wide (and this was even sometimes used to define the inch [ citation needed ] include Afrikaans : duim; Catalan : polzada ("inch") and polze ("thumb"); Czech : palec ("thumb"); Danish and Norwegian : tomme ("inch") tommel ("thumb"); Dutch : duim; French : pouce; Hungarian : hüvelyk; Italian : pollice; Portuguese : polegada ("inch") and polegar ("thumb"); Slovak : palec ("thumb"); Spanish : pulgada ("inch") and pulgar ("thumb"); Swedish : tum ("inch") and tumme ("thumb"); and Russian : дюйм ("duim").). Examples
Catalan is a Western Romance language derived from Vulgar Latin and named after the medieval Principality of Catalonia, in northeastern modern Spain. It is the only official language of Andorra, and a co-official language of the Spanish autonomous communities of Catalonia, the Balearic Islands and Valencia. It also has semi-official status in the Italian comune of Alghero. It is also spoken in the eastern strip of Aragon, in some villages of Region of Murcia called Carche and in the Pyrénées-Orientales department of France. These territories are often called Països Catalans or "Catalan Countries".
Czech, historically also Bohemian is a West Slavic language of the Czech–Slovak group. Spoken by over 10 million people, it serves as the official language of the Czech Republic. Czech is closely related to Slovak, to the point of mutual intelligibility to a very high degree, as well as Polish. Like other Slavic languages, Czech is a fusional language with a rich system of morphology and relatively flexible word order. Its vocabulary has been extensively influenced by Latin and German.
The inch is a commonly used customary unit of length in the United States,Canada, and the United Kingdom. It is also used in Japan for electronic parts, especially display screens. In most of continental Europe, the inch is also used informally as a measure for display screens. For the United Kingdom, guidance on public sector use states that, since 1 October 1995, without time limit, the inch (along with the foot) is to be used as a primary unit for road signs and related measurements of distance (with the possible exception of clearance heights and widths) and may continue to be used as a secondary or supplementary indication following a metric measurement for other purposes.
The international standard symbol for inch is in (see ISO 31-1, Annex A) but traditionally the inch is denoted by a double prime, which is often approximated by double quotes, and the foot by a prime, which is often approximated by an apostrophe. For example, three feet two inches can be written as 3′ 2″. (This is akin to how the first and second "cuts" of the hour and degree are likewise indicated by prime and double prime symbols.)
Subdivisions of an inch are typically written using dyadic fractions with odd number numerators; for example, two and three eighths of an inch would be written as 2+3/″ and not as 2.375″ nor as 2+6/″. However for engineering purposes fractions are commonly given to three or four places of decimals and have been for many years.
1 international inch is equal to:
The earliest known reference to the inch in England is from the Laws of Æthelberht dating to the early 7th century, surviving in a single manuscript, the Textus Roffensis from 1120.Paragraph LXVII sets out the fine for wounds of various depths: one inch, one shilling, two inches, two shillings, etc.
An Anglo-Saxon unit of length was the barleycorn. After 1066, 1 inch was equal to 3 barleycorns, which continued to be its legal definition for several centuries, with the barleycorn being the base unit. One of the earliest such definitions is that of 1324, where the legal definition of the inch was set out in a statute of Edward II of England, defining it as "three grains of barley, dry and round, placed end to end, lengthwise".
Similar definitions are recorded in both English and Welsh medieval law tracts. 184, 187, 189), are that "three lengths of a barleycorn is the inch".One, dating from the first half of the 10th century, is contained in the Laws of Hywel Dda which superseded those of Dyfnwal, an even earlier definition of the inch in Wales. Both definitions, as recorded in Ancient Laws and Institutes of Wales (vol i., pp.
King David I of Scotland in his Assize of Weights and Measures (c. 1150) is said to have defined the Scottish inch as the width of an average man's thumb at the base of the nail, even including the requirement to calculate the average of a small, a medium, and a large man's measures.However, the oldest surviving manuscripts date from the early 14th century and appear to have been altered with the inclusion of newer material.
In 1814, Charles Butler, a mathematics teacher at Cheam School, recorded the old legal definition of the inch to be "three grains of sound ripe barley being taken out the middle of the ear, well dried, and laid end to end in a row", and placed the barleycorn, not the inch, as the base unit of the English Long Measure system, from which all other units were derived.John Bouvier similarly recorded in his 1843 law dictionary that the barleycorn was the fundamental measure. Butler observed, however, that "[a]s the length of the barley-corn cannot be fixed, so the inch according to this method will be uncertain", noting that a standard inch measure was now (by his time) kept in the Exchequer chamber, Guildhall, and that was the legal definition of the inch.
This was a point also made by George Long in his 1842 Penny Cyclopædia, observing that standard measures had since surpassed the barleycorn definition of the inch, and that to recover the inch measure from its original definition, in the event that the standard measure were destroyed, would involve the measurement of large numbers of barleycorns and taking their average lengths. He noted that this process would not perfectly recover the standard, since it might introduce errors of anywhere between one hundredth and one tenth of an inch in the definition of a yard.
Before the adoption of the international yard and pound, various definitions were in use. In the United Kingdom and most countries of the British Commonwealth, the inch was defined in terms of the Imperial Standard Yard. The United States adopted the conversion factor 1 metre = 39.37 inches by an act in 1866.In 1893, Mendenhall ordered the physical realization of the inch to be based on the international prototype metres numbers 21 and 27, which had been received from the CGPM, together with the previously adopted conversion factor.
In 1930, the British Standards Institution adopted an inch of exactly 25.4 mm. The American Standards Association followed suit in 1933. By 1935, industry in 16 countries had adopted the "industrial inch" as it came to be known.
In 1946, the Commonwealth Science Congress recommended a yard of exactly 0.9144 metres for adoption throughout the British Commonwealth. This was adopted by Canada in 1951; the United States on 1 July 1959; Australia in 1961, effective 1 January 1964; and the United Kingdom in 1963, effective on 1 January 1964. The new standards gave an inch of exactly 25.4 mm, 1.7 millionths of an inch longer than the old imperial inch and 2 millionths of an inch shorter than the old US inch.
The United States retains the 1/-metre definition for survey purposes, producing a 2 millionth part difference between standard and US survey inches. This is approximately 1/ inch per mile. In fact, 12.7 kilometres is exactly 500,000 standard inches and exactly 499,999 survey inches. This difference is significant when doing calculations in State Plane Coordinate Systems with coordinate values in the hundreds of thousands or millions of feet.
Before the adoption of the metric system, several European countries had customary units whose name translates into "inch". The French pouce measured 27.0 mm, at least when applied to describe the calibre of artillery pieces. The Amsterdam foot (voet) consisted of 11 Amsterdam inches (duim). The Amsterdam foot is about 8% shorter than an English foot.[ citation needed ]
The now obsolete Scottish inch (Scottish Gaelic : òirleach), 1/ of a Scottish foot, was about 1.0016 imperial inches (about 25.4406 mm). It was used in the popular expression Gie 'im an inch, an he'll tak an ell, in English "Give him an inch and he'll take an ell", first published as "For when I gave you an inch, you tooke an ell" by John Heywood in 1546. (The ell, equal to 37 inches (about 940 mm), was in use in England until 1685.) Modern versions of the saying include "Give him an inch and he'll take a mile" and "Give him an inch and he'll take a yard".
The acre is a unit of land area used in the imperial and US customary systems. It is traditionally defined as the area of one chain by one furlong, which is exactly equal to 10 square chains, 1⁄640 of a square mile, or 43,560 square feet, and approximately 4,047 m2, or about 40% of a hectare. Based upon the International yard and pound agreement of 1959, an acre may be declared as exactly 4,046.8564224 square metres. The acre is a statute measure in the United States and was formerly one in the United Kingdom and almost all countries of the former British Empire, although informal use continues.
The gallon is a unit of measurement for volume and fluid capacity in both the US customary units and the British imperial systems of measurement. Three significantly different sizes are in current use:
The kilogram is the base unit of mass in the metric system, formally the International System of Units (SI), having the unit symbol kg. It is a widely used measure in science, engineering, and commerce worldwide, and is often called a kilo. The kilogram is almost exactly the mass of one litre of water.
The litre or liter is an SI accepted metric system unit of volume equal to 1 cubic decimetre (dm3), 1,000 cubic centimetres (cm3) or 1/1,000 cubic metre. A cubic decimetre occupies a volume of 10 cm × 10 cm × 10 cm and is thus equal to one-thousandth of a cubic metre.
The metre or meter is the base unit of length in the International System of Units (SI). The SI unit symbol is m. The metre is defined as the length of the path travelled by light in a vacuum in 1/299 792 458 of a second.
The mile is an English unit of length of linear measure equal to 5,280 feet, or 1,760 yards, and standardised as exactly 1,609.344 metres by international agreement in 1959.
The pound or pound-mass is a unit of mass used in the imperial, United States customary and other systems of measurement. Various definitions have been used; the most common today is the international avoirdupois pound, which is legally defined as exactly 0.45359237 kilograms, and which is divided into 16 avoirdupois ounces. The international standard symbol for the avoirdupois pound is lb; an alternative symbol is lbm, #, and ℔ or ″̶.
The tonne, commonly referred to as the metric ton in the United States and Canada, is a non-SI metric unit of mass equal to 1,000 kilograms or one megagram. It is equivalent to approximately 2,204.6 pounds, 1.102 short tons (US) or 0.984 long tons (UK). Although not part of the SI, the tonne is accepted for use with SI units and prefixes by the International Committee for Weights and Measures.
United States customary units are a system of measurements commonly used in the United States. The United States customary system developed from English units which were in use in the British Empire before the U.S. became an independent country. However, the United Kingdom's system of measures was overhauled in 1824 to create the imperial system, changing the definitions of some units. Therefore, while many U.S. units are essentially similar to their Imperial counterparts, there are significant differences between the systems.
The yard is an English unit of length, in both the British imperial and US customary systems of measurement, that comprises 3 feet or 36 inches.
The foot is a unit of length in the imperial and US customary systems of measurement. Since the International Yard and Pound Agreement of 1959, one foot is defined as 0.3048 meter exactly. In customary and imperial units, the foot comprises 12 inches and three feet compose a yard.
The quart is an English unit of volume equal to a quarter gallon. It is divided into two pints or four cups. Historically, the exact size of the quart has varied with the different values of gallons over time and in reference to different commodities. Presently, three kinds of quarts remain in use: the liquid quart and dry quart of the US customary system and the imperial quart of the British imperial system. All are roughly equal to one metric litre.
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 in use include the International System of Units (SI), the modern form of the metric system, the imperial system, and United States customary units.
The following systems arose from earlier systems, and in many cases utilise parts of much older systems. For the most part they were used to varying degrees in the Middle Ages and surrounding time periods. Some of these systems found their way into later systems, such as the Imperial system and even SI. There were several types to measure that is
English units are the units of measurement that were used in England up to 1826, which evolved as a combination of the Anglo-Saxon and Roman systems of units. Various standards have applied to English units at different times, in different places, and for different applications.
A unit of measurement is a definite 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 be expressed as a multiple of the unit of measurement.
The international yard and pound are two units of measurement that were the subject of an agreement among representatives of six nations signed on 1 July 1959, namely the United States, United Kingdom, Canada, Australia, New Zealand and the Union of South Africa. The agreement defined the yard as exactly 0.9144 meters and the pound as exactly 0.45359237 kilograms.
The imperial system of measurement and the US customary system of measurement are both derived from an earlier English system of measurement which in turn can be traced back to Ancient Roman units of measurement, and Carolingian and Saxon units of measure.
One Metre is equal to ... 30.371 inches"
The basic major dia is actually 1.309 in.