Editing Inch (section)

== Usage ==
===Imperial or hybrid countries===
The inch is a commonly used customary unit of length in the United States,<ref>{{cite web |url=http://corpus.byu.edu/coca/ |title=Corpus of Contemporary American English |website=Brigham Young University |location=US |access-date=5 December 2011}} lists 24,302 instances of inch(es) compared to 1548 instances of centimeter(s) and 1343 instances of millimeter(s).</ref> Canada,<ref>{{cite web |url=http://laws-lois.justice.gc.ca/PDF/W-6.pdf |title=Weights and Measures Act |page=37 |via=Justice Laws Website |location=Canada |year=1985 |access-date=11 January 2018}}</ref><ref>{{cite web |url=http://laws-lois.justice.gc.ca/eng/acts/W-6/page-2.html#h-4/ |title=Weights and Measures Act |page=2 |via=Justice Laws Website |location=Canada |date=1 August 2014 |access-date=18 December 2014}} Canadian units (5) The Canadian units of measurement are as set out and defined in Schedule II, and the symbols and abbreviations therefore are as added pursuant to subparagraph 6(1)(b)(ii).</ref> and the United Kingdom.<ref name=bis/> 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)<ref>{{cite web |url=http://www.legislation.gov.uk/uksi/2002/3113/schedule/2/made |title=The Traffic Signs Regulations and General Directions 2002 - No. 3113 - Schedule 2 - Regulatory Signs |publisher=The National Archives |location=UK |year=2002 |access-date=25 April 2013}}</ref> and may continue to be used as a secondary or supplementary indication following a metric measurement for other purposes.<ref name=bis>{{cite web |url=http://www.bis.gov.uk/assets/bispartners/nmo/docs/legislation/legislation/units-of-measurement/gnotes-for-public-sector-on-use-of-metric.pdf |archive-url=https://web.archive.org/web/20110704232045/http://www.bis.gov.uk/assets/bispartners/nmo/docs/legislation/legislation/units-of-measurement/gnotes-for-public-sector-on-use-of-metric.pdf |url-status=dead |archive-date=4 July 2011 |title=Guidance Note on the use of Metric Units of Measurement by the Public Sector |publisher=Department for Business Innovation and Skills |location=UK |year=2007 |access-date=12 December 2014}}</ref>

===Worldwide===
Inches are used for display screens (e.g. [[television]]s and computer monitors) worldwide. It is the official [[Japanese units of measurement#Imperial units|Japanese standard]] for electronic parts, especially display screens, and is the industry standard throughout continental Europe for display screens ([[Germany]] being one of few countries to supplement it with centimetres in most stores<ref>{{Cite web|url=https://www.otto.de/technik/fernseher/|title=Fernseher|publisher=[[Otto GmbH]]|language=de|access-date=28 December 2023}}</ref>).

Inches are commonly used to specify the diameter of vehicle wheel rims, and the corresponding inner diameter of tyres in [[tyre code]]s.<ref>{{Cite web|url=https://www.michelin.co.uk/auto/advice/tyre-basics/tyre-markings-explained|title=Tyre Sizing|access-date=14 May 2025}}</ref>

===Technical details===

The international standard symbol for inch is '''in''' (see [[ISO 31-1]], Annex A) but traditionally the inch is denoted by a [[Prime (symbol)|double prime]], which is often approximated by a [[quotation mark|double quote]] symbol, and the [[Foot (unit)|foot]] by a [[Prime (symbol)|prime]], which is often approximated by an [[apostrophe (mark)|apostrophe]]. For example; ''{{nowrap|three feet, two inches}}'' can be written as 3{{prime}} 2{{pprime}}. (This is akin to how the [[minute|first]] and [[second]] "cuts" of the [[hour]] are likewise indicated by prime and double prime symbols, and also the [[Minute of arc|first]] and [[Second of arc|second]] cuts of the [[Degree (angle)|degree]].)

Subdivisions of an inch are typically written using [[dyadic rational|dyadic fractions]] with odd number numerators; for example, ''{{nowrap|two and three-eighths of an inch}}'' would be written as {{sfrac|2|3|8}}{{pprime}} and not as 2.375{{pprime}} nor as {{sfrac|2|6|16}}{{pprime}}.  However, for engineering purposes fractions are commonly given to three or four places of decimals and have been for many years.<ref>{{cite book|last1=Flatchet|first1=E|last2=Petiet|first2=J|title=The student's guide to the locomotive engine|url=https://archive.org/details/studentsguideto00ptgoog|date=1849|publisher=John Williams and Co|page=xi|quote=One Metre is equal to ... 30.371 inches"}}</ref><ref>{{cite book|last=Parkinson|first=A C |title=Intermediate Engineering Drawing|date=1967|edition=sixth|page=11|quote=The basic major dia is actually 1.309 in.}}</ref>

=== Equivalents===
{{calculator|id=in|type=number|size=4|default=1}} international inch is equal to:
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* {{calculator|id=cm|type=plain|default=2.54|formula=in*2.54|decimals=1|NaN-text=0}} [[centimeter]]s (1 inch is exactly 2.54&nbsp;cm)
* {{calculator|id=mm|type=plain|default=25.4|formula=in*25.4|decimals=1|NaN-text=0}} [[millimetre]]s (1 inch is exactly 25.4&nbsp;mm)
* {{sfrac|{{calculator|id=numeratorfeet|type=plain|default=1|formula=in|NaN-text=0}}|12}} or {{calculator|id=feet|type=plain|default=0.08333|formula=in/12|NaN-text=0}} [[foot (unit)|feet]] (approximately)
* {{sfrac|{{calculator|id=numeratoryards|type=plain|default=1|formula=in|NaN-text=0}}|36}} or {{calculator|id=yard|type=plain|default=0.02777|formula=in/36|NaN-text=0}} [[yard]]s (approximately)
* {{calculator|id=tenths|type=plain|default=10000|formula=in*10000|NaN-text=0}} '[[Thousandth of an inch#Tenths|tenths]]'{{efn|A tenth of a [[thousandth of an inch|thou]], used in [[machining]].}}
* {{calculator|id=thou|type=plain|default=1000|formula=in*1000|NaN-text=0}} [[Thousandth of an inch|thou]]{{efn|Used in [[machining]] and [[papermaking]].}} or mil{{efn|Formerly used in [[American English]] but now often avoided to prevent confusion with [[millimetre]]s.}}
* {{calculator|id=points|type=plain|default=100|formula=in*100|NaN-text=0}} points{{efn|Used by the Australian [[Bureau of Meteorology]] for measuring rainfall until 1973<ref>{{cite web |url=http://www.bom.gov.au/climate/cdo/about/definitionsrain.shtml |title=Climate Data Online – definition of rainfall statistics |publisher=[[Bureau of Meteorology]] |location=Australia |access-date=10 June 2012}}</ref>}} or gries{{efn|name=locke|Part of [[John Locke]]'s proposal for decimalization of English measures<ref>{{citation |last=Locke |first=John |author-link=John Locke |display-authors=0 |contribution=Of Human Understanding |page=[https://books.google.com/books?id=3n8PAAAAQAAJ&pg=PA293 293] |title=The Works of John Locke Esq., ''Vol. I'' |location=London |publisher=John Churchill |date=1714 |url=https://books.google.com/books?id=3n8PAAAAQAAJ }}.</ref>}}
* {{calculator|id=pointsTypography|type=plain|default=72|formula=in*72|NaN-text=0}} [[Point (typography)|PostScript point]]s{{efn|The typographic point was originally {{sfrac|1|9}} of the height of a (capital) letter ([[cap height]]) but later acquired a number of different absolute definitions; see [[Point (typography)#History|Point (typography) § History]] for details.}}
* {{calculator|id=line10|type=plain|default=10|formula=in*10|NaN-text=0}},{{efn|Used in [[gunmaking]].}}<ref group=lower-alpha name=locke/> {{calculator|id=line12|type=plain|default=12|formula=in*12|NaN-text=0}},{{efn|Used in [[botany]].}} or {{calculator|id=line40|type=plain|default=40|formula=in*40|NaN-text=0}}{{efn|Used in [[button (clothing)|button]] manufacturing.}} [[line (unit)|lines]]
* {{calculator|id=pica|type=plain|default=6|formula=in*6|NaN-text=0}} [[Pica (typography)|computer picas]]{{efn|Used in [[typography]].}}
* {{calculator|id=barleycorn|type=plain|default=3|formula=in*3|NaN-text=0}} [[Barleycorn (unit)|barleycorns]]{{efn|Used in American and British [[shoe size]]s.}}
* {{calculator|id=ussurveyin|type=plain|default=0.999998|formula=in*0.999998|NaN-text=0}} [[#US survey inches|US survey inches]]
* {{sfrac|{{calculator|id=numeratorPalm|type=plain|default=1|formula=in|NaN-text=0}}|3}} or {{calculator|id=palms|type=plain|default=0.333|formula=in/3|NaN-text=0}} [[palm (unit)|palms]] (approximately)
* {{sfrac|{{calculator|id=numeratorhand|type=plain|default=1|formula=in|NaN-text=0}}|4}} or {{calculator|id=hand|type=plain|default=0.25|formula=in/4|NaN-text=0}} [[hand (unit)|hands]]{{efn|Used in measuring the height of [[horse]]s.}}
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