Editing Decimalisation (section)

{{short description|Converting a measuring system to a decimal base}}
{{About|decimalisation of currency and measurement|the system of library classification|Dewey Decimal Classification|the development of the number system|Decimal}}
'''Decimalisation''' or '''decimalization''' (see [[American and British English spelling differences|spelling differences]]) is the conversion of a system of currency or of weights and measures to units related by [[Power of 10|powers of 10]].

Most countries have decimalised their currencies, converting them from non-decimal sub-units to a [[decimal]] system, with one basic currency unit and sub-units that are valued relative to the basic unit by a power of [[10 (number)|10]], most commonly 100 and exceptionally 1000, and sometimes at the same time, changing the name of the currency and/or the conversion rate to the new currency. 

Today, only two countries have ''de jure'' non-decimal currencies, these being [[Mauritania]] (where 1 [[Mauritanian ouguiya|ouguiya]] = 5 [[khoums]]) and [[Madagascar]] (where 1 [[Malagasy ariary|ariary]] = 5 [[iraimbilanja]]): <ref>{{Cite web|url=http://famouswonders.com/malagasy-ariary/|title=Malagasy Ariary|website=Famous Wonders|date=4 April 2011|access-date=2016-12-13}}</ref> however, these currencies are ''de facto'' decimal as the value of both currencies' main unit is now so low that the sub-units are too small to be of any practical use, and coins of these sub-units are no longer used.  

[[Russia]] was the first country to convert to a decimal currency when it decimalised under Tsar [[Peter the Great]] in 1704, resulting in the silver [[Russian ruble|ruble]] being equal to 100 copper [[kopek]]s.<ref>{{Cite web|url=http://numismatics.org/pocketchange/peter/|title=The Reign of Peter the Great as Represented in the ANS Collection |website=Pocket Change |publisher=[[American Numismatic Society]] |date=12 November 2020}}</ref><ref name=":0">''Encyclopædia Britannica''. 15th ed.<!--assumed based on date – CD-ROM edition?--> Volume 25. 1994.</ref>{{page needed<!--don't actually need page – name of entry is enough-->|date=December 2024}}

For weights and measures, this is also called [[metrication]], replacing traditional units that are related in other ways, such as those formed by successive doubling or halving, or by more arbitrary [[conversion factor]]s. Units of physical measurement, such as length and mass, were decimalised with the introduction of the [[metric system]], which has been adopted by almost all countries (with the prominent exceptions of the [[Metrication in the United States|United States]], and, to a lesser extent, the [[United Kingdom]] and [[Canada]]). Thus, a kilometre is 1,000 metres, while a mile is 1,760 yards. [[Electrical units]] are decimalised worldwide. 

Common [[units of time]] remain undecimalised. Although an [[French Republican calendar|attempt to decimalise them]] was made during the [[French Revolution]], this proved to be unsuccessful and was quickly abandoned.