Bitcoin’s smallest standard unit, equal to one hundred-millionth of a bitcoin, is the satoshi.
One bitcoin contains 100,000,000 satoshis, often shortened to sats. The unit is named after Satoshi Nakamoto, the pseudonymous creator of Bitcoin. Using satoshis allows software and users to represent very small payments without relying on long decimal fractions of a bitcoin.
The satoshi is especially useful when bitcoin’s market price is high or when a transaction involves small amounts. Wallets may display balances in bitcoin, satoshis, or both. The exact integer-based representation also helps software avoid some rounding problems that can occur when financial amounts are handled as floating-point numbers.
A satoshi is not a separate cryptocurrency and does not have its own independent blockchain. It is a denomination of bitcoin, like a smaller unit of a national currency. Some services use “sat” or “sats” in informal language, while the formal plural can be written “satoshis.” Bitcoin’s protocol also has limits on how finely amounts can be divided.