Editing Imperial units (section)

===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 {{val|0.914398415}} metres.<ref>Sears et al. 1928. ''Phil Trans A'', 227:281.</ref>
{| class="wikitable" style="margin-right:0"
|+ Table of length equivalent units
! Unit
! Abbr. or symbols
! Relative to previous
! Feet
! [[Metres]]
! Notes
|-
![[twip]]
|
|
|align=right | {{frac|17280}}
|align=right | {{val|0.00001763|end={{overline|8}}}}
|typographic measure
|-
![[thou (length)|thou]]
|th
|1.44 twip
|align=right| {{frac|{{val|12000}}}}
|align=right| {{val|0.0000254}}
|
Abbreviation of "thousandth of an inch". Also known as ''mil''.<ref name="jerrard">Jerrard and McNeill, Dictionary of Scientific Units, second edition, Chapman and Hall; cites first appearance in print in Journal of the Institution of Electrical Engineers<!-- This journal was known Journal of the Society of Telegraph Engineers in 1872--> (G.B.) vol. 1, page 246 (1872).</ref>
|-
![[Barleycorn (unit)|barleycorn]]
|
| {{nowrap|{{Fraction|333|1|3}} th}}
|align="right" | {{frac|36}}
|align="right" | {{val|0.0084|end={{overline|6}}}}
| {{nowrap|{{Fraction|1|3}} in}}
|-
![[inch]]
|in ([[″]])
| {{val|3|u=Bc}}
| align="right" | {{frac|12}}
| align="right" | {{val|0.0254}}
| 1 metre ≡ 39 {{frac|47|127}} inches
|-
![[Hand (unit)|hand]]
|hh
| {{val|4|u=inch}}
|align="right" | {{frac|3}}
|align="right" | {{val|0.1016}}
| Used to measure the height of horses
|-
![[Foot (unit)|foot]]
|ft ([[′]])
| {{val|3|u=hand}}
|align=right | 1
|align=right | {{val|0.3048}}
|12 in
|-
![[yard]]
|yd
| {{val|3|u=foot}}
|align=right| 3
|align=right| {{val|0.9144}}
| Defined as exactly {{val|0.9144|u=metres}} by the [[international yard and pound]] agreement of 1959
|-
![[Chain (unit)|chain]]
|ch
| {{val|22|u=yard}}
|align=right | 66
|align=right | {{val|20.1168}}
| {{val|100|u=links}}, {{val|4|u=rods}}, or {{frac|10}} of a furlong. The distance between the two [[wicket]]s on a [[cricket pitch]].
|-
![[furlong]]
|fur
| {{val|10|u=chain}}
|align=right| {{val|660}}
|align=right| {{val|201.168}}
| {{val|220|u=yards}}
|-
![[mile]]
|mi
| {{val|8|u=furlong}}
|align=right | {{val|5280}}
|align=right | {{val|1609.344}}
| {{val|1760|u=yards}} or {{val|80|u=chain}}
|-
![[league (unit)|league]]
|lea
| {{val|3|u=mile}}
|align=right | {{val|15840}}
|align=right | {{val|4828.032}}
|
|-
| colspan="6" style="text-align:center;" | '''Maritime units'''
|- valign=top
![[fathom]]
|ftm
| {{val|2.02667|u=yard}}
|align=right | {{val|6.0761}}
|align=right | {{val|1.852}}
| The British Admiralty in practice used a fathom of {{val|6|u=foot}}. This was despite its being {{frac|1000}} of a nautical mile (i.e. {{val|6.08|u=foot}}) until the adoption of the international nautical mile.<ref name="fath">The exact figure was {{val|6.08|u=foot}}, but {{val|6|u=foot}} was in use in practice. The commonly accepted definition of a fathom was always 6 feet. The conflict was inconsequential, as Admiralty nautical charts designated depths shallower than {{val|5|u=fathom}} in feet on older imperial charts. Today, all charts worldwide are metric, except for USA Hydrographic Office charts, which use feet for all depth ranges.</ref>
|- valign=top
![[cable length|cable]]
|
| {{val|100|u=fathom}}
|align=right | {{val|607.61}}
|align=right | {{val|185.2}}
| One tenth of a nautical mile. Equal to {{val|100|u=fathom}} under the strict definition.
|- valign=top
![[nautical mile]]
|nmi
| {{val|10|u=cables}}
|align=right | {{val|6076.1}}
|align=right | {{val|1852}}
| Used for measuring distances at sea (and also in aviation) and approximately equal to one [[arc minute]] of a [[great circle]]. Until the adoption of the international definition of {{val|1852|u=metre}} in 1970, the British nautical (Admiralty) mile was defined as {{val|6080|u=foot}}.<ref>The [[nautical mile]] was not readily expressible in terms of any of the intermediate units, because it was derived from the circumference of the Earth (like the original metre).</ref>
|-
| colspan="6" style="text-align:center;" | '''Gunter's survey units (17th century onwards)'''
|-
![[link (unit)|link]]
|
| {{val|7.92|u=inch}}
|align=right | {{frac|66|100}}
|align=right | {{val|0.201168}}
| {{frac|100}} of a chain and {{frac|{{val|1000}}}} of a furlong
|-
![[Rod (unit)|rod]]
|
| {{val|25|u=links}}
|align=right | {{frac|66|4}}<!-- odd fraction is intentional; it is to show the relative value of the unit more clearly in this subsection of the table -->
|align=right | {{val|5.0292}}
| The rod is also called ''pole'' or ''perch'' and is equal to {{nowrap|{{frac|5|1|2}} yards}}
|}