Satoshi

Key points

• Satoshi is the smallest unit into which a bitcoin can be divided, as defined in the network's own protocol.
• One satoshi equals one hundred-millionth of a bitcoin, meaning each bitcoin divides into one hundred million satoshis.
• This divisibility makes it possible to transact very small amounts, even when the price of a whole bitcoin is high.

What is a satoshi?

Satoshi is the smallest fraction of a bitcoin. Just as a real divides into centavos, bitcoin divides into much smaller units, and the satoshi is the smallest of them. The name honors Satoshi Nakamoto, the pseudonym behind Bitcoin's creation. Working in satoshis is the natural way to handle small amounts on the network.

How it works

The Bitcoin protocol records values internally in satoshis, not in whole bitcoins. Each bitcoin corresponds to one hundred million satoshis, giving eight decimal places of precision. Transferring a fraction of a bitcoin is, in practice, transferring a whole number of satoshis, which avoids rounding ambiguities in the ledger.

This granularity matters because the price of a whole bitcoin can be high. Without divisibility into satoshis, it would be difficult to use the network for small amounts. Thinking in satoshis also makes it easier to compare fees and small amounts, which would be full of zeros if always written in bitcoins.

Over time, as the value of each bitcoin fluctuates, talking in satoshis becomes a practical way to express everyday prices and payments within the ecosystem.

Why it matters

For payments and microtransactions, divisibility into satoshis is what makes Bitcoin usable for small amounts. For anyone operating on the network, understanding that everything is counted in satoshis helps interpret fees and amounts precisely, without confusion over decimal places. In low-value payments, it is common to quote prices directly in satoshis, which avoids dealing with many decimal places and makes amounts more intuitive day to day.

Risks and limitations

The satoshi is Bitcoin's smallest native unit, so values below it cannot be represented directly on the main chain. When network fees rise, transferring just a few satoshis can become economically unviable, since the transaction cost exceeds the amount sent. Layer-two solutions emerged in part to enable very small payments cheaply. Even so, fine divisibility into satoshis is a clear advantage of Bitcoin as a means of payment.