Convert Cambodian Riel (KHR) to South African Rand (ZAR)

1 cambodian_riel = 1 cambodian_riel

Exchange rates last updated: February 11, 2026 05:00

Conversion Formula for Cambodian Riel to South African Rand

The formula of conversion of Cambodian Riel to South African Rand is very simple. To convert Cambodian Riel to South African Rand, we can use this simple formula:

1 Cambodian Riel = 253.6335224414 South African Rand

1 South African Rand = 0.0039426965 Cambodian Riel

One Cambodian Riel is equal to 253.6335224414 South African Rand. So, we need to multiply the number of Cambodian Riel by 253.6335224414 to get the no of South African Rand. This formula helps when we need to change the measurements from Cambodian Riel to South African Rand

Cambodian Riel to South African Rand Conversion

The conversion of Cambodian Riel currency to South African Rand currency is very simple. Since, as discussed above, One Cambodian Riel is equal to 253.6335224414 South African Rand. So, to convert Cambodian Riel to South African Rand, we must multiply no of Cambodian Riel to 253.6335224414. Example:-

Cambodian Riel South African Rand
0.01 Cambodian Riel 2.5363352244 South African Rand
0.1 Cambodian Riel 25.3633522441 South African Rand
1 Cambodian Riel 253.6335224414 South African Rand
2 Cambodian Riel 507.2670448828 South African Rand
3 Cambodian Riel 760.9005673241 South African Rand
5 Cambodian Riel 1,268.1676122069 South African Rand
10 Cambodian Riel 2,536.3352244138 South African Rand
20 Cambodian Riel 5,072.6704488276 South African Rand
50 Cambodian Riel 12,681.676122069 South African Rand
100 Cambodian Riel 25,363.3522441381 South African Rand
500 Cambodian Riel 126,816.7612206903 South African Rand
1,000 Cambodian Riel 253,633.5224413807 South African Rand

Details for Cambodian Riel (KHR) Currency

Introduction : The Cambodian Riel (KHR) is the official currency of Cambodia. Represented by the symbol ៛, the riel plays an important role in the daily lives of Cambodians, especially for small-scale transactions and local trade. It is issued by the National Bank of Cambodia and exists in both coins and banknotes, with denominations suited to a variety of purchases. While the US dollar is also widely used throughout Cambodia for larger transactions, the riel is deeply woven into the country’s economy and culture. Its colorful banknotes feature images of temples, historical figures, and symbols of national heritage.

History & Origin : The history of the Cambodian Riel is shaped by the country’s complex political past. The first version of the riel was introduced in 1955, replacing the French Indochinese piastre. However, during the Khmer Rouge regime in the 1970s, money was abolished entirely, and the economy collapsed. Following the regime’s fall, a new version of the riel was reintroduced in 1980 with the goal of rebuilding the monetary system. Over the decades, Cambodia’s central bank has worked to improve the riel’s stability and security. Despite the prevalence of the US dollar, efforts have been made to promote the use of the riel through salary payments and local pricing.

Current Use : In Cambodia, the riel is widely used for everyday transactions, especially in rural areas and local markets. It is most commonly used for small purchases such as food, transportation, and utilities. Meanwhile, the US dollar circulates in parallel and is often preferred for larger expenses, including hotel stays, electronic purchases, and rent. This dual-currency system has persisted for years, but the Cambodian government and central bank have recently increased their push for de-dollarization, encouraging the use of the riel to strengthen national monetary policy. Today, digital wallets and mobile payments are also supporting broader riel adoption among younger and urban populations.

Details of Cambodia

Cambodia, officially known as the Kingdom of Cambodia, is a Southeast Asian nation bordered by Thailand, Laos, Vietnam, and the Gulf of Thailand. It is a country rich in culture, history, and natural beauty. The capital and largest city, Phnom Penh, is the economic, political, and cultural center of the country. Cambodia's landscape is a blend of lush rainforests, fertile plains, and the mighty Mekong River that runs through its heart.

One of Cambodia’s most iconic features is the ancient Angkor Wat temple complex, a UNESCO World Heritage Site and one of the largest religious monuments in the world. Built during the Khmer Empire, this site attracts millions of visitors annually and symbolizes the country’s proud historical legacy. The Cambodian people, known for their warmth and resilience, have a rich tradition of arts, dance, and craftsmanship rooted in both Buddhist and Hindu influences.

Despite enduring the trauma of the Khmer Rouge era in the 1970s, Cambodia has made significant progress in recent decades. The country has experienced steady economic growth driven by textiles, agriculture, construction, and tourism. While poverty remains an issue in some regions, development efforts and foreign investment have helped improve infrastructure, healthcare, and education.

The official language is Khmer, and the dominant religion is Theravada Buddhism, which plays a central role in Cambodian society. The nation observes vibrant festivals such as Khmer New Year and Pchum Ben, showcasing its deep cultural identity. With its combination of ancient wonders, dynamic cities, and welcoming people, Cambodia offers a compelling glimpse into the past while moving steadily toward a brighter future.

Details for South African Rand (ZAR) Currency

Introduction : The South African Rand (ZAR), symbolized as R, is the official currency of South Africa and is also accepted in neighboring countries like Lesotho, Eswatini, and Namibia. The rand is subdivided into 100 cents and is issued by the South African Reserve Bank (SARB). Known for its colorful banknotes and coins featuring iconic wildlife and historical figures, the rand plays a crucial role in South Africa’s diversified economy. It is actively traded on global forex markets and reflects the country’s financial performance, commodity exports, and political developments. The rand is central to everyday commerce and serves as a gateway currency for southern Africa.

History & Origin : The South African Rand was introduced in 1961, replacing the South African pound as the country transitioned into a republic and moved away from British colonial monetary ties. Named after the Witwatersrand—a ridge where most of South Africa’s gold deposits were discovered—the rand historically reflected the strength of the nation’s mining and export sectors. Initially pegged to the US dollar, the currency has floated freely since the 1970s. Over the decades, the rand has weathered numerous fluctuations influenced by gold prices, sanctions during apartheid, and post-apartheid economic reforms. Today, it serves as a key regional currency and a benchmark for emerging market investors.

Current Use : The rand is the primary medium of exchange in South Africa, used in all sectors from retail to real estate. It is also widely accepted in the Common Monetary Area (CMA), including Namibia, Lesotho, and Eswatini, which peg their own currencies to it. The rand is involved in international trade, particularly in commodities like gold, platinum, and coal. Its value is sensitive to global market trends, domestic political shifts, and economic policy changes. With increasing digitization, the rand is also used in mobile banking and fintech platforms. Despite its volatility, it remains a reliable and widely circulated currency in the region.

Details of South Africa

South Africa, located at the southern tip of the African continent, is a nation of rich diversity, complex history, and significant economic and cultural influence. It shares borders with Namibia, Botswana, Zimbabwe, Mozambique, Eswatini, and encloses the landlocked country of Lesotho. Known for its varied landscapes ranging from beaches and savannas to deserts and mountains, South Africa is often referred to as the 'Rainbow Nation' for its multicultural society.

The country’s history is marked by its colonial past and the apartheid era, a system of institutionalized racial segregation that lasted from 1948 to 1994. Nelson Mandela’s election as the first Black president in 1994 marked the start of a democratic era. Since then, South Africa has made strides in reconciliation, economic development, and human rights, although it continues to face challenges such as inequality, unemployment, and corruption.

South Africa is Africa’s second-largest economy, driven by a mix of mining, manufacturing, agriculture, tourism, and financial services. It is one of the world's leading producers of gold, platinum, and other precious minerals. Johannesburg, the country’s financial capital, and Cape Town, known for its scenic beauty and cultural vibrancy, are among its major urban centers. Pretoria serves as the administrative capital, while Bloemfontein is the judicial capital.

With 11 official languages and a rich blend of African, European, and Asian influences, South Africa boasts a vibrant cultural scene. The country is known for its music, dance, literature, and cuisine. It also plays a key role in regional diplomacy, continental trade, and environmental preservation efforts. Despite its challenges, South Africa remains a resilient, influential, and dynamic nation with a significant role on the African and global stage.

Convert Cambodian Riel to Other Currencies

Cambodian Riel to United Arab Emirates DirhamUnited Arab Emirates Dirham to Cambodian Riel
Cambodian Riel to Afghan AfghaniAfghan Afghani to Cambodian Riel
Cambodian Riel to Albanian LekAlbanian Lek to Cambodian Riel
Cambodian Riel to Armenian DramArmenian Dram to Cambodian Riel
Cambodian Riel to Netherlands Antillean GuilderNetherlands Antillean Guilder to Cambodian Riel
Cambodian Riel to Angolan KwanzaAngolan Kwanza to Cambodian Riel
Cambodian Riel to Argentine PesoArgentine Peso to Cambodian Riel
Cambodian Riel to Australian DollarAustralian Dollar to Cambodian Riel
Cambodian Riel to Aruban FlorinAruban Florin to Cambodian Riel
Cambodian Riel to Azerbaijani ManatAzerbaijani Manat to Cambodian Riel
Cambodian Riel to Bosnia Herzegovina Convertible MarkBosnia Herzegovina Convertible Mark to Cambodian Riel
Cambodian Riel to Barbadian DollarBarbadian Dollar to Cambodian Riel
Cambodian Riel to Bangladeshi TakaBangladeshi Taka to Cambodian Riel
Cambodian Riel to Bulgarian LevBulgarian Lev to Cambodian Riel
Cambodian Riel to Bahraini DinarBahraini Dinar to Cambodian Riel
Cambodian Riel to Burundian FrancBurundian Franc to Cambodian Riel
Cambodian Riel to Bermudan DollarBermudan Dollar to Cambodian Riel
Cambodian Riel to Brunei DollarBrunei Dollar to Cambodian Riel
Cambodian Riel to Bolivian BolivianoBolivian Boliviano to Cambodian Riel
Cambodian Riel to Brazilian RealBrazilian Real to Cambodian Riel
Cambodian Riel to Bahamian DollarBahamian Dollar to Cambodian Riel
Cambodian Riel to Bhutanese NgultrumBhutanese Ngultrum to Cambodian Riel
Cambodian Riel to Botswanan PulaBotswanan Pula to Cambodian Riel
Cambodian Riel to Belarusian RubleBelarusian Ruble to Cambodian Riel
Cambodian Riel to Belize DollarBelize Dollar to Cambodian Riel
Cambodian Riel to Canadian DollarCanadian Dollar to Cambodian Riel
Cambodian Riel to Congolese FrancCongolese Franc to Cambodian Riel
Cambodian Riel to Swiss FrancSwiss Franc to Cambodian Riel
Cambodian Riel to Chilean Unit Of Account UfChilean Unit Of Account Uf to Cambodian Riel
Cambodian Riel to Chilean PesoChilean Peso to Cambodian Riel
Cambodian Riel to Chinese Yuan OffshoreChinese Yuan Offshore to Cambodian Riel
Cambodian Riel to Chinese YuanChinese Yuan to Cambodian Riel
Cambodian Riel to Colombian PesoColombian Peso to Cambodian Riel
Cambodian Riel to Costa Rican ColonCosta Rican Colon to Cambodian Riel
Cambodian Riel to Cuban Convertible PesoCuban Convertible Peso to Cambodian Riel
Cambodian Riel to Cuban PesoCuban Peso to Cambodian Riel
Cambodian Riel to Cape Verdean EscudoCape Verdean Escudo to Cambodian Riel
Cambodian Riel to Czech Republic KorunaCzech Republic Koruna to Cambodian Riel
Cambodian Riel to Djiboutian FrancDjiboutian Franc to Cambodian Riel
Cambodian Riel to Danish KroneDanish Krone to Cambodian Riel
Cambodian Riel to Dominican PesoDominican Peso to Cambodian Riel
Cambodian Riel to Algerian DinarAlgerian Dinar to Cambodian Riel
Cambodian Riel to Egyptian PoundEgyptian Pound to Cambodian Riel
Cambodian Riel to Eritrean NakfaEritrean Nakfa to Cambodian Riel
Cambodian Riel to Ethiopian BirrEthiopian Birr to Cambodian Riel
Cambodian Riel to EuroEuro to Cambodian Riel
Cambodian Riel to Fijian DollarFijian Dollar to Cambodian Riel
Cambodian Riel to Falkland Islands PoundFalkland Islands Pound to Cambodian Riel
Cambodian Riel to British Pound SterlingBritish Pound Sterling to Cambodian Riel
Cambodian Riel to Georgian LariGeorgian Lari to Cambodian Riel
Cambodian Riel to Guernsey PoundGuernsey Pound to Cambodian Riel
Cambodian Riel to Ghanaian CediGhanaian Cedi to Cambodian Riel
Cambodian Riel to Gibraltar PoundGibraltar Pound to Cambodian Riel
Cambodian Riel to Gambian DalasiGambian Dalasi to Cambodian Riel
Cambodian Riel to Guinean FrancGuinean Franc to Cambodian Riel
Cambodian Riel to Guatemalan QuetzalGuatemalan Quetzal to Cambodian Riel
Cambodian Riel to Guyanaese DollarGuyanaese Dollar to Cambodian Riel
Cambodian Riel to Hong Kong DollarHong Kong Dollar to Cambodian Riel
Cambodian Riel to Honduran LempiraHonduran Lempira to Cambodian Riel
Cambodian Riel to Haitian GourdeHaitian Gourde to Cambodian Riel
Cambodian Riel to Hungarian ForintHungarian Forint to Cambodian Riel
Cambodian Riel to Indonesian RupiahIndonesian Rupiah to Cambodian Riel
Cambodian Riel to Israeli New SheqelIsraeli New Sheqel to Cambodian Riel
Cambodian Riel to Manx PoundManx Pound to Cambodian Riel
Cambodian Riel to Indian RupeeIndian Rupee to Cambodian Riel
Cambodian Riel to Iraqi DinarIraqi Dinar to Cambodian Riel
Cambodian Riel to Iranian RialIranian Rial to Cambodian Riel
Cambodian Riel to Icelandic KronaIcelandic Krona to Cambodian Riel
Cambodian Riel to Jersey PoundJersey Pound to Cambodian Riel
Cambodian Riel to Jamaican DollarJamaican Dollar to Cambodian Riel
Cambodian Riel to Jordanian DinarJordanian Dinar to Cambodian Riel
Cambodian Riel to Japanese YenJapanese Yen to Cambodian Riel
Cambodian Riel to Kenyan ShillingKenyan Shilling to Cambodian Riel
Cambodian Riel to Kyrgystani SomKyrgystani Som to Cambodian Riel
Cambodian Riel to Comorian FrancComorian Franc to Cambodian Riel
Cambodian Riel to North Korean WonNorth Korean Won to Cambodian Riel
Cambodian Riel to South Korean WonSouth Korean Won to Cambodian Riel
Cambodian Riel to Kuwaiti DinarKuwaiti Dinar to Cambodian Riel
Cambodian Riel to Cayman Islands DollarCayman Islands Dollar to Cambodian Riel
Cambodian Riel to Kazakhstani TengeKazakhstani Tenge to Cambodian Riel
Cambodian Riel to Laotian KipLaotian Kip to Cambodian Riel
Cambodian Riel to Lebanese PoundLebanese Pound to Cambodian Riel
Cambodian Riel to Sri Lankan RupeeSri Lankan Rupee to Cambodian Riel
Cambodian Riel to Liberian DollarLiberian Dollar to Cambodian Riel
Cambodian Riel to Lesotho LotiLesotho Loti to Cambodian Riel
Cambodian Riel to Libyan DinarLibyan Dinar to Cambodian Riel
Cambodian Riel to Moroccan DirhamMoroccan Dirham to Cambodian Riel
Cambodian Riel to Moldovan LeuMoldovan Leu to Cambodian Riel
Cambodian Riel to Malagasy AriaryMalagasy Ariary to Cambodian Riel
Cambodian Riel to Macedonian DenarMacedonian Denar to Cambodian Riel
Cambodian Riel to Myanma KyatMyanma Kyat to Cambodian Riel
Cambodian Riel to Mongolian TugrikMongolian Tugrik to Cambodian Riel
Cambodian Riel to Macanese PatacaMacanese Pataca to Cambodian Riel
Cambodian Riel to Mauritanian OuguiyaMauritanian Ouguiya to Cambodian Riel
Cambodian Riel to Mauritian RupeeMauritian Rupee to Cambodian Riel
Cambodian Riel to Maldivian RufiyaaMaldivian Rufiyaa to Cambodian Riel
Cambodian Riel to Malawian KwachaMalawian Kwacha to Cambodian Riel
Cambodian Riel to Mexican PesoMexican Peso to Cambodian Riel
Cambodian Riel to Malaysian RinggitMalaysian Ringgit to Cambodian Riel
Cambodian Riel to Mozambican MeticalMozambican Metical to Cambodian Riel
Cambodian Riel to Namibian DollarNamibian Dollar to Cambodian Riel
Cambodian Riel to Nigerian NairaNigerian Naira to Cambodian Riel
Cambodian Riel to Nicaraguan CordobaNicaraguan Cordoba to Cambodian Riel
Cambodian Riel to Norwegian KroneNorwegian Krone to Cambodian Riel
Cambodian Riel to Nepalese RupeeNepalese Rupee to Cambodian Riel
Cambodian Riel to New Zealand DollarNew Zealand Dollar to Cambodian Riel
Cambodian Riel to Omani RialOmani Rial to Cambodian Riel
Cambodian Riel to Panamanian BalboaPanamanian Balboa to Cambodian Riel
Cambodian Riel to Peruvian Nuevo SolPeruvian Nuevo Sol to Cambodian Riel
Cambodian Riel to Papua New Guinean KinaPapua New Guinean Kina to Cambodian Riel
Cambodian Riel to Philippine PesoPhilippine Peso to Cambodian Riel
Cambodian Riel to Pakistani RupeePakistani Rupee to Cambodian Riel
Cambodian Riel to Polish ZlotyPolish Zloty to Cambodian Riel
Cambodian Riel to Paraguayan GuaraniParaguayan Guarani to Cambodian Riel
Cambodian Riel to Qatari RialQatari Rial to Cambodian Riel
Cambodian Riel to Romanian LeuRomanian Leu to Cambodian Riel
Cambodian Riel to Serbian DinarSerbian Dinar to Cambodian Riel
Cambodian Riel to Russian RubleRussian Ruble to Cambodian Riel
Cambodian Riel to Rwandan FrancRwandan Franc to Cambodian Riel
Cambodian Riel to Saudi RiyalSaudi Riyal to Cambodian Riel
Cambodian Riel to Solomon Islands DollarSolomon Islands Dollar to Cambodian Riel
Cambodian Riel to Seychellois RupeeSeychellois Rupee to Cambodian Riel
Cambodian Riel to Sudanese PoundSudanese Pound to Cambodian Riel
Cambodian Riel to Swedish KronaSwedish Krona to Cambodian Riel
Cambodian Riel to Singapore DollarSingapore Dollar to Cambodian Riel
Cambodian Riel to Saint Helena PoundSaint Helena Pound to Cambodian Riel
Cambodian Riel to Sierra Leonean LeoneSierra Leonean Leone to Cambodian Riel
Cambodian Riel to Somali ShillingSomali Shilling to Cambodian Riel
Cambodian Riel to Surinamese DollarSurinamese Dollar to Cambodian Riel
Cambodian Riel to South Sudanese PoundSouth Sudanese Pound to Cambodian Riel
Cambodian Riel to Sao Tome And Principe DobraSao Tome And Principe Dobra to Cambodian Riel
Cambodian Riel to Salvadoran ColonSalvadoran Colon to Cambodian Riel
Cambodian Riel to Syrian PoundSyrian Pound to Cambodian Riel
Cambodian Riel to Swazi LilangeniSwazi Lilangeni to Cambodian Riel
Cambodian Riel to Thai BahtThai Baht to Cambodian Riel
Cambodian Riel to Tajikistani SomoniTajikistani Somoni to Cambodian Riel
Cambodian Riel to Turkmenistani ManatTurkmenistani Manat to Cambodian Riel
Cambodian Riel to Tunisian DinarTunisian Dinar to Cambodian Riel
Cambodian Riel to Tongan PaangaTongan Paanga to Cambodian Riel
Cambodian Riel to Turkish LiraTurkish Lira to Cambodian Riel
Cambodian Riel to Trinidad And Tobago DollarTrinidad And Tobago Dollar to Cambodian Riel
Cambodian Riel to New Taiwan DollarNew Taiwan Dollar to Cambodian Riel
Cambodian Riel to Tanzanian ShillingTanzanian Shilling to Cambodian Riel
Cambodian Riel to Ukrainian HryvniaUkrainian Hryvnia to Cambodian Riel
Cambodian Riel to Ugandan ShillingUgandan Shilling to Cambodian Riel
Cambodian Riel to United States DollarUnited States Dollar to Cambodian Riel
Cambodian Riel to Uruguayan PesoUruguayan Peso to Cambodian Riel
Cambodian Riel to Uzbekistan SomUzbekistan Som to Cambodian Riel
Cambodian Riel to Venezuelan Bolivar SoberanoVenezuelan Bolivar Soberano to Cambodian Riel
Cambodian Riel to Vietnamese DongVietnamese Dong to Cambodian Riel
Cambodian Riel to Vanuatu VatuVanuatu Vatu to Cambodian Riel
Cambodian Riel to Samoan TalaSamoan Tala to Cambodian Riel
Cambodian Riel to Cfa Franc BeacCfa Franc Beac to Cambodian Riel
Cambodian Riel to Silver Troy OunceSilver Troy Ounce to Cambodian Riel
Cambodian Riel to Gold Troy OunceGold Troy Ounce to Cambodian Riel
Cambodian Riel to East Caribbean DollarEast Caribbean Dollar to Cambodian Riel
Cambodian Riel to Special Drawing RightsSpecial Drawing Rights to Cambodian Riel
Cambodian Riel to Cfa Franc BceaoCfa Franc Bceao to Cambodian Riel
Cambodian Riel to Palladium OuncePalladium Ounce to Cambodian Riel
Cambodian Riel to Cfp FrancCfp Franc to Cambodian Riel
Cambodian Riel to Platinum OuncePlatinum Ounce to Cambodian Riel
Cambodian Riel to Yemeni RialYemeni Rial to Cambodian Riel
Cambodian Riel to South African RandSouth African Rand to Cambodian Riel
Cambodian Riel to Zambian KwachaZambian Kwacha to Cambodian Riel

FAQ on Cambodian Riel (KHR) to South African Rand (ZAR) Conversion:

What is the Symbol of Cambodian Riel and South African Rand?

The symbol for Cambodian Riel is '៛', and for South African Rands, it is 'R'. These symbols are used to denote in everyday currency analysis.

How to convert Cambodian Riel(s) to South African Rand(es)?

To convert Cambodian Riel(s) to South African Rand(es), multiply the number of Cambodian Riels by 253.63352244138 because one Cambodian Riel equals 253.63352244138 South African Rands.
Formula: South African Rands = Cambodian Riels × 253.63352244138.
This is a standard rule used in conversions.

How to convert South African Rand(es) to Cambodian Riel(s) ?

To convert South African Rand(es) to Cambodian Riel(s), divide the number of South African Rands by 253.63352244138, since, 1 Cambodian Riel contains exactly 253.63352244138 South African Rand(es).
Formula: Cambodian Riels = South African Rand(s) ÷ 253.63352244138.
It’s a common calculation in conversions.

How many Cambodian Riel(s) are these in an South African Rand(es) ?

There are 0.0039426964952203 Cambodian Riels in one South African Rand. This is derived by dividing 1 South African Rand by 253.63352244138, as 1 Cambodian Riel equals 253.63352244138 South African Rand(s).
Formula: Cambodian Riel = South African Rands ÷ 253.63352244138.
It’s a precise currency conversion method.

How many South African Rand(es) are these in an Cambodian Riel(s) ?

There are exactly 253.63352244138 South African Rands in one Cambodian Riel. This is a fixed value used in the measurement system.
Formula: South African Rand(s) = Cambodian Riels × 253.63352244138.
It's one of the most basic conversions.

How many South African Rand in 10 Cambodian Riel?

There are 2536.3352244138 South African Rands in 10 Cambodian Riels. This is calculated by multiplying 10 by 253.63352244138.
Formula: 10 Cambodian Riels × 253.63352244138 = 2536.3352244138 South African Rands.
This conversion is helpful for measurements.

How many South African Rand(s) in 50 Cambodian Riel?

There are 12681.676122069 South African Rands in 50 Cambodian Riels. One can calculate it by multiplying 50 by 253.63352244138.
Formula: 50 Cambodian Riels × 253.63352244138 = 12681.676122069 South African Rands.
This conversion is used in many applications.

How many South African Rand(s) in 100 Cambodian Riel?

There are 25363.352244138 South African Rand(s) in 100 Cambodian Riels. Multiply 100 by 253.63352244138 to get the result.
Formula: 100 Cambodian Riels × 253.63352244138 = 25363.352244138 South African Rand(s).
This is a basic currency conversion formula.