Satoshi (sat)

A satoshi, often shortened to "sat", is the smallest unit of bitcoin recorded on the blockchain. One bitcoin equals 100,000,000 satoshis, so one sat is 0.00000001 BTC. The unit is named after Satoshi Nakamoto, the pseudonymous creator of Bitcoin.

Thinking in sats is useful because a whole bitcoin is expensive. Many wallets let you display balances and fees in sats, and network fees are quoted in satoshis per virtual byte (sat/vB) of transaction data. On the Lightning Network, payments can even be denominated in thousandths of a satoshi (millisatoshis) internally, though they settle on-chain in whole sats.

Buying sats rather than whole coins is how most retail investors acquire bitcoin. Exchanges let you spend a fixed rupee or dollar amount and credit you the corresponding fraction.