The dollar sign ($; also known as the peso sign) is a currency symbol consisting of a capital crossed with one or two vertical strokes ( or depending on typeface), used to represent the base unit of account of various currencies around the world, including most currencies denominated "dollar" or "peso". The explicitly double-barred sign is called cifrão in the Portuguese language.
The sign is also used in several compound currency symbols, such as the Brazilian real (R$) and the United States dollar (US$): in local use, the nationality prefix is usually omitted. In countries that have other currency symbols, the US dollar is often assumed and the "US" prefix omitted.
The one- and two-stroke versions are often considered mere stylistic (typeface) variants, although in some places and epochs one of them may have been specifically assigned, by law or custom, to a specific currency. The Unicode computer encoding standard defines a single code for both.
In most English-speaking countries that use that symbol, it is placed to the left of the amount specified, e.g. "$1", read as "one dollar".
History Early history
How the dollar sign came to represent the Spanish American peso is uncertain. There are several competing hypotheses: The most widely accepted theory holds that among the very many latinate scribal abbreviations the dollar sign developed out of an abbreviation for the Spanish and Spanish-American for pesos. A study of late 18th- and early 19th-century manuscripts shows that the s gradually came to be written over the p, developing into a close equivalent to the '$' mark. Oliver Pollock, a wealthy Irish trader and early supporter of the American Revolution, used the abbreviation "ps", sometimes run together in a way that almost exactly resembled the dollar sign, in a letter dated 1778. There are documents showing the common use of the two-stroke version in Portugal already by 1775. Another hypothesis derives the sign from a depiction of the Pillars of Hercules, a classical symbol for two sides of the Strait of Gibraltar, with a ribbon wrapped around each pillar (or both pillars) in the form of an 'S'. This device is a support element of the Spanish coat of arms, and appeared on the most common real de ocho coins circulating at the time in the Americas and Europe; namely, those minted at the Potosí mint in Bolivia, which operated from 1573–1825. Indeed, one of the names used for Spanish dollars in Qing Dynasty China was .
A variant of the above theory claims that the sign comes from the mark of the mint at Potosí, where a large portion of the Spanish Empire's silver was mined. A feature on these coins were the superimposed. The core of this monogram is a (single-stroked) '$' sign.
Yet another hypothesis notes that the English word "dollar" for the Spanish piece of eight originally came (through Dutch daalder) from Joachimsthaler or thaler, a similar large German silver coin that was widely used in Europe. It is therefore conjectured that the dollar sign derived from a symbol consisting of a superimposing 'S' and 'I' or 'J' that was used to denote the German silver coin. notes that such a symbol used for that dollar unit appears in the of An Introduction to Merchants' Accounts by John Collins printed at the end of Gerard de Malynes’ Lex MercatoriaJohn Collins, An Introduction to Merchants' Accounts, 1653 also uses the symbol. and was also used for the mark (Hamburg mark banco) in particular in the first half of the 19th century. Alternatively, the symbol could have come from a snake and cross emblem on the thaler coins.
Less likely theories The following theories seem to have been discredited or contradicted by documentary evidence:
James Alton James proposed that the symbol with two strokes was adapted from a 1778 design by financier Robert Morris, found in his letters to Pollock. Henrietta Larson suggested that the sign could derive from a combination of the Greek character "psi" (ψ) and 'S'. Another theory claims that the sign started off as a monogram of "US", with a narrow 'U' superimposed on the 'S'; the bottom part of the 'U' would have been lost, producing the dollar sign with two vertical lines. Florian Cajori found this theory mentioned in 1876 letters to the journal Notes and Queries. Henry R. Towne begins his 1886 essay on management stating this theory. This was also claimed by Ayn Rand in her 1957 novel Atlas Shrugged; in Rand's conjecture is that the "US" monogram was imprinted on the money bags used by the United States Mint. noted that the captors of slaves in Spanish territories sometimes branded enslaved people with a symbol very similar to a one-barred dollar sign. Esclavo is Spanish for "slave," and clavo means nail. A dollar sign would then be 'S' + clavo, (''). A theory often cited in Portuguese speaking countries is that the 'S' part of the doubly-stroked sign is a schematic representation of the path followed by the Umayyad Caliphate general Tariq Ibn Ziyad in his conquest of the Visigoth kingdom in 711 CE, and the two strokes represent the Pillars of Hercules that he would have crossed along that path. That symbol would have been engraved in coins commemorating his victory, and then became symbolic of currency in general. Encyclopaedia Britannica describes the hypothesis that the symbol is derived from the Arabic numeral "8" in reference to the Spanish dollar or "piece of eight" as a "popular theory" for which there is a lack of documentary evidence."dollar sign" on Encyclopaedia Britannica website, viewed 2026-04-11
1770s - present The symbol appears in business correspondence in the 1770s from the West Indies referring to the Spanish American peso, also known as "Spanish dollar" or "piece of eight" in British America. The Spanish coins provided the model for the currency that the United States adopted in 1792, and for the larger coins of the new Spanish American republics, such as the Mexican peso, Argentine peso, Peruvian real, and Bolivian sol coins.
With the Coinage Act of 1792, the United States Congress created the U.S. dollar, defining "each to be of the value of a Spanish milled dollar as the same is now current" but a variety of foreign coins were deemed to be legal tender until the Coinage Act of 1857 ended this status.
The earliest U.S. dollar coins did not have any dollar symbol. The first occurrence in print is claimed to be from 1790s, by a Philadelphia printer Archibald Binny, creator of the Monticello typeface. The $1 United States Note issued by the United States in 1869 included a large symbol consisting of a 'U' with the right bar overlapping an 'S' like a single-bar dollar sign, as well as a very small double-stroke dollar sign in the legal warning against forgery see picture.
Currencies that use the dollar sign As symbol of the currency The numerous currencies called "dollar" use the dollar sign to express money amounts. The sign is also generally used for the many currencies called "peso" (except the Philippine peso, which uses the symbol "₱"). Within a country the dollar/peso sign may be used alone when referring to the country's own currency. In other cases, and to avoid ambiguity in international usage, it is usually combined with other glyphs, e.g. CA$ or Can$ for Canadian dollar. Particularly in professional contexts, the unambiguous ISO 4217 three letter code (AUD, MXN, USD, etc.) is preferred.
The dollar sign, alone or in combination with other glyphs, is or was used to denote several currencies with other names, including:
Brazilian cruzeiro (various currencies, all defunct): ₢$, CR, Cr, NCr, etc. Brazilian real: R$ Ethiopian birr (until 1976): E$ Macanese pataca: MOP$ Nicaraguan córdoba: C$ Samoan tālā (a transliteration of the word dollar): $ Tongan paʻanga: T$ Malaya and British Borneo dollar (1957–1967): $ Malaysian ringgit (1967–1997): $, M$, M New Taiwan dollar: NT$, 元, $ South Vietnamese đồng (1953–1975): $,
Prefix or suffix In the United States, Mexico, Australia, Argentina, Chile, Colombia, New Zealand, Hong Kong, Pacific Island nations, and English-speaking Canada, the sign is written before the number ("$5"), even though, when the word is written out or spoken, it is put after the number ("five dollars", ""). The exception is French-speaking Canada, where the dollar symbol usually appears after the number, the same as the spoken order, e.g., "" for "".
Use in the Portuguese Empire
In Portugal, Brazil, and other parts of the Portuguese Empire, the two-stroke variant of the sign named (; plural ) has been used as the thousands separator in the national currency, the real (plural "réis", abbreviated "Rs."). For instance, would be equivalent to . This usage is attested in 1775, but may be older by a century or more.João Joseph Du Beux (1775): Receipt of 270$000 Rs. for purchase by of 50 volumes of the Acta Santorum by the College of the Carmo of Coimbra. Quote: "Recebemos [...] a quantia de Duzentos Settenta mil réis[...] por Clareza passamos este Coimbra 15 de Março de 1775. São Rs". Cartório do Colégio do Carmo, Maço 35, n.o 17. apud ALMEIDA, Manuel Lopes in "Livro, livreiros, impressores em documentos da Universidade", Arquivo de Bibliografia Portuguesa, ano X–XII, Atlântida, Coimbra, 1964–66, n o 37–48. The cifrão is always written with two vertical lines like , and is the official sign of the Cape Verdean escudo (ISO 4217: CVE).
In 1911, Portugal redefined the national currency as the escudo, worth , and divided into 100 ; but the cifrão continued to be used as the decimal separator, so that meant or 123 escudos and 50 centavos. This usage ended in 2002 when the country switched to the euro. (A similar scheme to use a letter symbol instead of a decimal point is used by the RKM code in electrical engineering since 1952.)
Cape Verde, a republic and former Portuguese colony, similarly switched from the real to their local escudo and centavos in 1914, and retains the cifrão usage as decimals separator . Local versions of the Portuguese escudo were for a time created also for other overseas colonies, including East Timor (1958–1975), Portuguese India (1958–1961), Angola (1914–1928 and 1958–1977), Mozambique (1914–1980), Portuguese Guinea (1914–1975), and São Tomé and Príncipe (1914–1977); all using the cifrão as decimals separator.
Brazil retained the real and the cifrão as thousands separator until 1942, when it switched to the Brazilian cruzeiro, with comma as the decimals separator. The dollar sign, officially with one stroke but often rendered with two, was retained as part of the currency symbol , so one would write for 13 cruzeiros and 50 centavos.(1960): Price on the front cover of the 1960-05-07 issue of O Cruzeiro magazine, reproduced on the Muzeez website on 2016-12-105. Accessed on 2021-08-14.
The cifrão was formerly used by the Portuguese escudo (ISO: PTE) before its replacement by the euro and by the Portuguese Timor escudo (ISO: TPE) before its replacement by the Indonesian rupiah and the US dollar.Lisbon-tourist-guide.com. "Portuguese Escudo ." 2008. In Portuguese and Cape Verdean usage, the is placed as a decimal point between the escudo and values.Banco de Cabo Verde. "Moedas ." Accessed 25 Feb 2011. The name originates in the Arabic (), meaning 'zero'.
Outside the Portuguese cultural sphere, the South Vietnamese đồng before 1975 used a method similar to the cifrão to separate values of đồng from its decimal subunit xu. For example, meant 7 đồng and 50 xu.
One stroke vs. two strokes
In some places and at some times, the one- and two-stroke variants have been used in the same contexts to distinguish between the U.S. dollar and other local currency, such as the former Portuguese escudo.