Satoshi Converter — BTC, sats, USD & gwei

What a satoshi actually is

A satoshi is the smallest piece of a bitcoin you can hold or send. One bitcoin splits into exactly one hundred million of them, so a single satoshi is 0.00000001 BTC. The unit is named after Satoshi Nakamoto, the pseudonymous author of the Bitcoin white paper, and it exists for a simple reason: as bitcoin’s price rises, whole coins become an awkward way to talk about everyday amounts. It is far easier to say “5,000 sats” than “0.00005 BTC”, and the Lightning Network — where people tip, pay and stream value in tiny increments — leans on sats almost exclusively.

A quick sense of scale

It helps to anchor a few reference points: 100 sats is a rounding error, 1,000 sats buys a coffee-sized tip on Lightning, 100,000 sats is one “bit” of common shorthand at 0.001 BTC, and 100,000,000 sats is a full coin. Type any of these into the calculator above and the dollar value fills in at the live rate, so you can see at a glance what a given pile of sats is worth today rather than doing the decimal arithmetic in your head.

Gwei and wei, for Ethereum

Ethereum uses the same idea with different names. Its base unit is the wei, and there are 10¹⁸ of them in one ETH — an absurdly small unit that exists so the protocol never has to use fractions internally. The unit you will actually meet is the gwei (one billion wei, or 0.000000001 ETH), because that is how gas fees are quoted. When a wallet says a transfer costs “20 gwei”, it means 20 gwei per unit of gas; a standard 21,000-gas send therefore costs 420,000 gwei, which is 0.00042 ETH. Switching between ETH, gwei and wei above makes those gas estimates concrete.

The mistakes worth avoiding

Two slip-ups catch people out. The first is a misplaced decimal: bitcoin has eight decimal places and ETH has eighteen, so one stray zero changes an amount by a factor of ten. Always re-read the figure before you send. The second is forgetting that the dollar column is live — it tracks the market second by second, so the value of your sats now is not the value they had this morning. Use it to understand size, not as a fixed quote.

General information, not financial advice. The unit conversions are exact; USD values are live and fluctuate. On-chain transactions are irreversible — always double-check the amount and the network before you send.