Non-decimal currencies

A non-decimal currency is one which has sub-units that are a non-decimal fraction of the main unit.

Today, only two countries in the world use non-decimal currencies. These are Mauritania (1 ouguiya = 5 khoums) and Madagascar (1 ariary = 5 iraimbilanja). In both cases the value of the main unit is so low that the sub-unit is too small to be of any practical use and coins of the sub-unit are no longer used.

All other contemporary currencies are either decimal or have no sub-units at all.

Historic

Historically, the use of decimal sub-units was the exception rather than the rule. Decimalised currencies show an advantage in accounting, because amounts are written down and calculated using the decimal numeral system (but when another numeral system is used, such as the vigesimal system that was common among ancient Mesoamerican civilizations or the sexagesimal system used by the ancient Mesopotamians, this advantage disappears). However, decimalised currencies are less advantageous in every day life. The principal advantage of most non-decimal currencies is that they are more easily divided up, particularly into 3 and 4, than decimal currencies. A currency with 10 minor units to the major unit is neither divisible into 3 or 4. A currency with 100 minor units to the major unit is still not divisible by 3 and furthermore 100 may be an uncomfortably large number for some poorly educated people to deal with. For example: A third of a German Gulden (of 60 Kreuzer) is 20 Kreuzer while a third of a dollar is 33.333... cents. This flexibility is useful when trading and when sharing out sums of money. For this reason, many states chose to adopt non-decimal currencies based on divisions into sub-units such as 12 or 20, often with more than one tier of sub-units.

There is a second, less deliberate, way in which non-decimal currencies emerged. Often multiple currencies would operate concurrently within an economy with non-decimal exchanges rate between them. For example: Fundamental units like the Reichsthaler/ rixdollar/ riksdaler/ rijksdaalder/ rigsdaler were widely accepted as a medium of accounting - matching different and changing local coins in Stockholm, Copenhagen, Antwerp, or Cologne. Inflation developed locally with changing subdivisions. One thus divided the Riksdaler into 2 silver dalers in Sweden in 1700, the 1715-19 devaluation of the coin changed that ratio, the new calculation was from then onwards to 1776 a division of 1 Riksdaler matching 3 daler silvermint. Most currencies made no distinction between units of accounting and units represented by coins and thus created such shifts.

It is hence problematic to give the following list - it is a list of examples picked from different periods. Many of the subdivisions given below were subjected to historical changes.

The Russian ruble is often said to be the first decimalized currency, when Peter the Great established the ratio 1 ruble = 100 kopecks in 1701. The Japanese were in some sense earlier calculating with the silver momme and its decimal subunits - but then the momme was no coin at all but a unit of weight matching 3.75 g - the computations handled silver by weight. The British pound sterling was the last major currency to be decimalized, on February 15, 1971. An early proposal for decimalizing the pound in the 19th century envisaged a system of 1 Pound = 10 florins = 100 dimes = 1000 cents. However the only step taken at that time was the introduction in 1849 of a florin coin (the earliest examples actually bore the inscription "One Tenth of a Pound").

A partial listing of former non-decimal currencies (giving only units of account):
*Ancient Greece - 1 drachma = 6 obols
*France - 1 livre = 20 sols = 240 deniers
*German Coins
**Frankfurt - 1 Reichstaler = 90 Kreuzer = 360 Pfennig OR 1 Reichsgulden = 60 Kreuzer = 240 Pfennig
**Hannover - 1 Thaler = 36 Mariengroschen = 288 Pfennig
**Hamburg - 1 Thaler = 3 Mark = 48 Schilling = 96 Pfennig
*India - 1 rupee = 16 annas = 64 paise = 192 pies . Also, 1 gold mohur = 15 silver rupees
*Japan - separate gold, silver, and copper currencies, but linked during the Edo period
**Gold: 1 ryō = 4 bu = 16 shu
**Silver: 1 momme = 10 fun = 100 rin (1 ryō = officially 50 momme, market rates fluctuated with supply and demand and the value of the metal minted see [http://www.pierre-marteau.com/currency/coins/japanese.html| Japan's Currency at Marteau] )
**Copper: 1 kan = 1000 mon (1 ryō = 4000 mon; hence, 1 bu = 1 kan)
*Netherlands - 1 gulden = 20 stuivers = 160 duit = 320 penningen
*Ottoman Empire - 1 kuruş = 40 para = 120 akçe
*Poland - 1 złoty = 30 groschen
*Roman Empire - 1 aureus = 25 denarii = 100 sestertii = 400 asses = 1600 quadrans
*Siam (modern-day Thailand) - 1 tical = 4 salung = 8 fuang = 16 song phai = 32 phai = 64 att = 128 solot
*Spanish Empire - 1 peso = 8 reales (de plata fuerte) = 680 maravedíes (the pesos are the "pieces of eight" often referred to in stories about pirates, such as "Treasure Island", vellon means the coin minted of an alloy with a low silver content.)
*Switzerland - 1 Gulden Rheinisch = 15 or 16 (later also 17 or 18) Batzen or = 20 Schilling; 1 Batzen = 4 Kreuzer; 1 Schilling = 6 Angster = 12 Heller
*The United Kingdom and many countries formerly part of the British Empire - 1 pound = 20 shillings = 240 pence = 960 farthings - many named coins existed (see British coinage, but these were the units of account)

See [http://www.pierre-marteau.com/currency/converter.html| The Marteau Early 18th-Century Currency Converter] for non-decimal conversion tools (using the conversion rates of the period around 1700)

Computations in non-decimal currencies are notoriously tedious. Use The [http://www.pierre-marteau.com/currency/converter/app-pea.html| English Apples into Dutch Peers-Converter] to calculate with non-decimal currencies of your choice and definition.

Fictional non-decimal currencies

*Harry Potter - 1 Galleon = 17 Sickles = 493 Knuts
*Pern - Mark, no name for subdivisions, but occurs in denominations of 1/32, 1/16, 1/8, 1/4, 1/2, 1, 2, 5, and 10 marks (and a few 100 marks for large transactions)
* - 1 Royal Crest = 5 Silver Sovereigns = 25 Dollars = 50 Queen's Shillings = 100 Crowns = 400 Grouts = 6400 Pence, additionally 1 King's Shilling = 3 Crowns, and 1 Gold Sovereign = 3 Silver Sovereigns. The currency system is intentionally made inconveniently complex and only ever used at one point of the game.
*Hitchhiker's Guide to the Galaxy: The Triganic Pu, subdivided into eight Ningis. The Ningi is a "triangular rubber coin six thousand eight hundred miles a side" and hence nobody has ever owned enough Ningis to own one Pu.
* Gold-Pressed Latinum - 1 brick = 20 bars = 400 strips = 40,000 slips. 1 bar = 20 strips = 2,000 slips. 1 strip = 100 slips

ee also

* Decimalisation
* Decimal currency
* Denomination (currency)