All amounts in the blockchain are denominated in satoshi before being converted for display. The source code also uses satoshi when specifying an amount of bitcoin. When displaying an extremely fine fraction of a bitcoin, such as when calculating fee per byte or a faucet reward, the amount is displayed in satoshi for readability.
Although the satoshi is the finest amount that can be recorded in the blockchain, payment channels may need to make very granular payments and so are sometimes denominated in millisatoshi, which are one hundred billionths of a single bitcoin.
In January 2018, 1 Euro cent is worth approximately 83 satoshi.
The value of a bitcoin in satoshi was decided by Satoshi Nakamoto to be 100 million no later than November 2008.
On November 15, 2010, ribuck proposed that the one hundredth of a bitcoin (0.01 BTC) be called a Satoshi. Four months later he instead suggested that the one hundred millionth unit be called an austrian or a satoshi. The name satoshi caught on, and was widely adopted thereafter.
In December 2017, BIP-176 also proposed "Bits" be used as a standard term for 100 (one hundred) satoshis or 1/1,000,000 (one one-millionth) of a bitcoin.
Traditionally, the plural form has been simply satoshi, but the term satoshis is also popular and equally correct. If the plural form were to follow the rules of Japanese grammar, it may be pronounced as satoshisa, or simply satoshi.
Satoshi is often abbreviated to sat or s, although no currency symbol has been widely adopted. There are various proposed symbols:
|Reminiscent of the Japanese aesthetic, the closest character being 丰 meaning: "Bountiful - abundant, lush, bountiful, plenty, luxurious growth of grass" which suggests a vast amount of Satoshi are still left to mine. This symbol has been adopted by multiple Bitcoin services including satoshilabs.com (Trezor), SatoshiCap.net, pricedinbitcoin21.com, Thunderhub.io, bitcoinicons.com, thebitcoinmachines.com, and many more.|
|里||In Japanese names, this character can (rarely) be read "satoshi". It is an uncommon Chinese/Japanese character on its own, and an infrequent radical (kangxi #166). It can be seen as a radical in the common kanji 理 and 量, used in meaningful words like 理想 (ideals), 理論 (theory), 理性 (reason), 理科 (science), and 量 (quantity). "Satoshi" is a rare reading; more commonly it is read as "ri" or "sato".|
|シ||A Japanese katakana representing the syllable "shi". Note that this character is extremely common in Japanese, so it could cause confusion. Also, it can mean "death" in Japanese and Chinese.|
|㋛||As above, but circled to distinguish it from the katakana.|
|し||As above, but this is the hiragana instead of the katakana. This is even more common than シ in Japanese writing, however.|
|サ||A Japanese katakana represents the syllable "sa". Maybe it looks more reminiscent of a currency symbol than others. Note that this character is extremely common in Japanese, so it could cause confusion.|
- What is a 'Satoshi'? - Bitcoin Stack Exchange
- BitcoinTalk thread 407442. How did “satoshi” become the name of the base unit? 9 January 2014. Post 4415850.
- BitcoinTalk thread 819656. Why 1BTC should equal 10^8 satoshi ? 11 October 2014.
- BitcoinTalk thread 382374. Bitcoin source from November 2008. 23 December 2013.
- Binns, Will. "How do I calculate my transaction fee?". 21 Support. https://support.21.co/bitcoin/transactions-and-fees/how-do-i-calculate-my-transaction-fee. Retrieved 23 October 2017.
- Barnes, Samuel (9 April 2014). "Do These "Free Bitcoin" Sites Work?". CryptoCoinsNews. https://www.cryptocoinsnews.com/do-free-bitcoin-sites-work/. Retrieved 19 August 2015.
- Receiving and receiving payments
- BitcoinTalk thread 369. Official Bitcoin Unicode Character? 14 July 2010. Post 22160.
- BitcoinTalk thread 3311. More divisibility required - move the decimal point 10 February 2011. Post 46648.
- Bitcoin Wiki revision by theymos
- BitcoinTalk thread 289475. satoshii 9 September 2013. Post 3112861.