View source for Quart

{{Short description|Unit of volume with different values}}
{{Other uses}}
{{Distinguish|cord (unit)}}
{{redirect|Quarts|the mineral|Quartz}}
{{Use dmy dates|date=August 2019}}
{{Use American English|date=June 2017}}
{{Infobox unit
| name         = Quart
| image        = Quarts of milk (5092042245) (3).jpg
| caption      = One-quart milk jugs (top shelf); half-gallon (two-quart) milk jugs (bottom shelf)
| standard     = 
| quantity     = Volume
| symbol       = qt
| units_imp1   = SI-compatible units
| inunits_imp1 = {{convert|1|impqt|L|sigfig=8|disp=out}}
| units_imp2   = US customary units
| inunits_imp2 =  ≈{{thinsp}}{{convert|1|impqt|usqt|sigfig=7|disp=out}}
| units_imp3   = US customary units
| inunits_imp3 = ≈{{thinsp}}{{convert|1|impqt|in3|sigfig=7|disp=out}}
| units_us1    = SI-compatible units
| inunits_us1  = {{thinsp}}{{convert|1|usqt|L|sigfig=9|disp=out}}
| units_us2    = Imperial units
| inunits_us2  = ≈{{thinsp}}{{convert|1|usqt|impqt|sigfig=7|disp=out}}
| units_us3    = Imperial units
| inunits_us3  = {{convert|1|usqt|in3|sigfig=4|disp=out}}
| units_us4    = US dry quarts
| inunits_us4  = {{sfrac|92400|107521}} dry qt
}}

The '''quart''' (symbol: '''qt''')<ref>{{cite book |title=BS350:Part 1:1974 Conversion factors and tables Part 1. Basis of tables. Conversion factors |date=1974 |publisher=British Standards Institution |pages=10, 86}}</ref> is a [[unit of volume]] equal to a quarter of a [[gallon]]. Three kinds of quarts are currently used: the '''liquid quart''' and '''dry quart''' of the [[US customary system]] and the {{nowrap|'''imperial quart'''}} of the [[imperial unit|British imperial system]]. All are roughly equal to one [[liter]]. It is divided into two [[pint]]s or (in the US) four [[cup (unit)|cup]]s. Historically, the size of a quart has varied with the different values of gallons over time, and in the case of the dry quart, in reference to different commodities.

{{anchor|Etymology}}

==Name==
The term comes from the [[Latin]] {{lang|la|[[wikt:quartus|quartus]]}} (meaning one-quarter) via the [[French language|French]] {{lang|fr|[[wikt:quart#French|quart]]}}.  However, although the French word {{lang|fr|[[:fr:quart (unité)|quart]]}} has the same root, it frequently means something entirely different. In [[Canadian French]] in particular, the quart is called {{lang|fr|[[:fr:pinte|pinte]]}},<ref name=mesures /> while the [[pint]] is called {{lang|fr|[[:fr:chopine|chopine]]}}.<ref name=mesures />

==History==
{{main|Gallon}}
Since gallons of various sizes have historically been in use, the corresponding quarts have also existed with various sizes.

==Definitions and equivalencies==

=== Imperial quart ===
The imperial quart is equal to one-quarter of an imperial gallon of exactly {{val|4.54609|u=liters}}, i.e. {{val|1.1365225|u=liters}}. In the United Kingdom, goods may be sold by the quart if the equivalent metric measure is also given.<ref>{{cite web| url = http://www.legislation.gov.uk/ukpga/1985/72/section/8| title = Weights and Measures Act 1985, Section 8| publisher = [[Government of the United Kingdom]]| access-date = 15 November 2019| archive-date = 18 November 2019| archive-url = https://web.archive.org/web/20191118022519/http://www.legislation.gov.uk/ukpga/1985/72/section/8| url-status = live}}</ref>
{|
|-
|1 imperial quart&nbsp;||≡
|align=right|{{sfrac|1|4}}||imperial gallon
|-
|||≡
|align=right|2||imperial pints
|-
|||≡
|align=right|8||imperial [[Gill (unit)|gills]]
|-
|||≡
|align=right|40||imperial fluid ounces
|-
|||≡
|align=right|{{val|1.1365225}}||liters<ref name=UK-LEG>{{UK-LEG|path=uksi/1995/1804|title=Units of Measurement Regulations 1995|asmade=yes|access_date=3 May 2011}}</ref>{{efn|This has been the exact conversion since the redefinition of the imperial gallon in 1976 in the UK,<ref name=UK-LEG /> and in 1964 in Canada.}} 
|-
|||≈
|align=right|69.35486||cubic inches
|-
|||≈
|align=right|{{val|0.3002375}}||US gallons
|-
|||≈
|align=right|1.20095||US liquid quarts
|-
|||≈
|align=right|2.4019||US liquid pints
|-
|||≈
|align=right|9.6076||US [[Gill (unit)|gills]]
|-
|||≈
|align=right|38.4304||US fluid ounces
|-
|||≈
|align=right|{{val|1.0320567}}||US dry quarts
|-
|||≈
|align=right|{{val|2.0641135}}||US dry pints
|}

In [[Canadian French]], by federal law, the imperial quart is called {{lang|fr|[[Pint#Other pints|pinte]]}}.<ref>{{Cite web |url=http://www.ic.gc.ca/eic/site/mc-mc.nsf/eng/home |title=Measurement Canada |access-date=1 October 2012 |archive-date=10 August 2017 |archive-url=https://web.archive.org/web/20170810172405/http://www.ic.gc.ca/eic/site/mc-mc.nsf/eng/Home |url-status=live }}</ref><ref name=mesures>{{Cite web |url=http://www.ic.gc.ca/eic/site/mc-mc.nsf/fra/accueil |title=Mesures Canada |access-date=1 October 2012 |archive-date=20 January 2018 |archive-url=https://web.archive.org/web/20180120070033/http://www.ic.gc.ca/eic/site/mc-mc.nsf/fra/accueil |url-status=live }}</ref>

===US liquid quart===
In the United States, traditional length and volume measures have been legally standardized for commerce by the [[international yard and pound]] agreement of 1959, using the definition of 1 yard being 0.9144 [[meter (unit)|meters]]: from this definition the metric equivalents for inches, feet, miles, area measures, and measures of volume are determined. The US liquid quart is equal to one-quarter of a gallon of exactly 231 [[cubic inches]], i.e. 57.75 cubic inches or {{val|0.946352946|u=liters}}.<ref name="15USC205">[https://www.law.cornell.edu/uscode/text/15/205- "Authorized tables"] {{Webarchive|url=https://web.archive.org/web/20200823093359/https://www.law.cornell.edu/uscode/text/15/205 |date=23 August 2020 }}, [[United States Code]], Title 15, ch. 6, subchapter I, sec. 205, accessed 19 July 2008.</ref><ref name=NIST />
{|
|-cat
|1 US liquid quart&nbsp;||≡
|align=right|{{sfrac|1|4}}||US [[gallon]]
|-
|||≡
|align=right|2||US liquid [[pint]]s
|-
|||≡
|align=right|4||US [[Cup (unit)#United States|cups]]
|-
|||≡
|align=right|8||US [[Gill (unit)|gills]]
|-
|||≡
|align=right|32||US [[fluid ounce]]s
|-
|||≡
|align=right|{{val|0.946352946}}||liters<ref name=NIST>[http://physics.nist.gov/cuu/pdf/sp811.pdf Guide for the Use of the International System of Units (SI)] {{Webarchive|url=https://web.archive.org/web/20160603203340/http://physics.nist.gov/cuu/pdf/sp811.pdf |date=3 June 2016 }}—US government publication</ref><ref name=l&in>This has been the exact conversion since the 1964 redefinition of the liter and the 1959 redefinition of the inch.</ref>
|-
|||≡
|align=right|57.75|| [[cubic inch]]es<ref>One US gallon is defined as exactly 231 cubic inches.</ref>
|-
|||≈
|align=right|{{val|0.2081685}}||imperial gallons
|-
|||≈
|align=right|{{val|0.8326742}}||imperial quarts
|-
|||≈
|align=right|{{val|1.6653484}}||imperial pints
|-
|||≈
|align=right|{{val|6.6613935}}||imperial [[Gill (unit)|gills]]
|-
|||≈
|align=right|{{val|33.3069674}}||imperial fluid ounces
|-
|||≡
|align=right|{{sfrac|92400|107521}}||US dry quart
|-
|||≡
|align=right|1{{sfrac|77279|107521}}||US dry pints
|-
|}

=== US dry quart ===
In the United States, the [[dry measure|dry]] quart is equal to {{sfrac|1|32}} of a US bushel of exactly 2150.42 cubic inches, i.e. 67.200625 cubic inches or {{val|1.101220942715|u=liters}}. 
{|
|-
|1 US dry quart&nbsp;||≡
|align=right|{{sfrac|1|32}}||US [[bushel]]
|-
|||≡
|align=right|{{sfrac|1|8}}||US [[peck]]

|-
|||≡
|align=right|2||US dry pints
|-
|||≡
|align=right|{{val|1.101220942715}}||liters<ref name="NIST"/><ref name="l&in"/>
|-
|||≡
|align=right|{{val|67.200625}}||cubic inches
|-
|||≡
|align=right|{{sfrac|107521|369600}}||US gallon
|-
|||≡
|align=right|1{{sfrac|15121|92400}}||US liquid quarts
|-
|||≡
|align=right|2{{sfrac|15121|46200}}||US liquid pints
|-
|||≡
|align=right|9{{sfrac|3571|11550}}||US gills
|-
|||≡
|align=right|37{{sfrac|1367|5775}}||US fluid ounces
|-
|||≈
|align=right|{{val|0.2422347}}||imperial gallons
|-
|||≈
|align=right|{{val|0.968939}}||imperial quarts
|-
|||≈
|align=right|{{val|1.9378779}}||imperial pints
|-
|||≈
|align=right|{{val|7.7515118}}||imperial [[Gill (unit)|gills]]
|-
|||≈
|align=right|{{val|38.7575589}}||imperial fluid ounces
|-
|}

==Winchester quart==
The Winchester quart is an obsolescent measure:<ref>[http://www.hants.gov.uk/regulatory/tradingstandards/wmhistory.html Trading Standards – Weights and Measures of the City of Winchester<!-- Bot generated title -->] {{webarchive |url=https://web.archive.org/web/20090122070517/http://www.hants.gov.uk/regulatory/tradingstandards/wmhistory.html |date=22 January 2009 }}</ref> it was originally equal to two imperial quarts (half of an imperial gallon) or exactly {{val|2.273045|u=litres}}, but was later metricated to {{val|2.5|u=litres}} (2.2 imperial quarts). Despite its name, it is unrelated to the [[Winchester measure]].<ref>{{Cite web |title=Units: W |url=https://www.ibiblio.org/units/dictW.html |access-date=2025-02-18 |website=www.ibiblio.org}}</ref>

The 2.5{{nbsp}}L bottles in which laboratory chemicals are supplied are sometimes referred to as [[Winchester (bottle)|Winchester quart bottles]], although these contain 10% more than a traditional Winchester quart.

==Reputed quart==
The reputed quart was a measure equal to two-thirds of an imperial quart (one-sixth of an imperial gallon), or exactly 0.757681{{overline|6}} liters, which is only 0.08% larger than one [[Fifth_(unit)|US fifth]] (exactly 0.7570823568 liters).

The reputed quart was previously recognized as a standard size of wine bottle in the United Kingdom, and is only about 1% larger than the current standard wine bottle of 0.75{{nbsp}}L.<ref>{{cite book|title=Oxford English Dictionary|url=http://www.oed.com/view/Entry/163235?redirectedFrom=reputed+quart#eid25894027|access-date=24 December 2014|chapter=Reputed, adj. (b)|archive-date=24 September 2015|archive-url=https://web.archive.org/web/20150924085514/http://www.oed.com/view/Entry/163235?redirectedFrom=reputed+quart#eid25894027|url-status=live}}</ref><ref>{{cite web|title=Reputed quart|url=http://sizes.com/units/quart_reputed.htm|publisher=Sizes – The Online Quantinary|access-date=24 December 2014|archive-date=26 September 2015|archive-url=https://web.archive.org/web/20150926141342/http://sizes.com/units/quart_reputed.htm|url-status=live}}</ref>

==Notes==
{{Notelist}}

==References==
{{Reflist}}

== External links ==
* {{Wiktionary-inline|quart}}
* {{Commons category-inline}}

{{Imperial units}}
{{United States Customary Units}}

[[Category:Alcohol measurement]]
[[Category:Cooking weights and measures]]
[[Category:Customary units of measurement in the United States]]
[[Category:Imperial units]]
[[Category:Units of volume]]