GlossaryIntermediate
Wei
The smallest denomination of Ether, with 1 ETH equal to 10^18 wei.
Wei is the smallest denomination of Ether (ETH), Ethereum's native asset, named after cryptography pioneer Wei Dai. One ETH is equal to 10^18 (one quintillion) wei.
Ethereum transaction fees and smart-contract values are typically calculated internally in wei for precision, then commonly displayed in more human-readable units — most often gwei (10^9 wei) for gas prices specifically. See Kaavon's "Gwei" glossary definition for that more commonly-displayed unit.
Examples
- A gas price is commonly expressed in gwei rather than wei simply for readability, since 1 gwei equals 1 billion wei.
- Smart contracts generally handle ETH amounts internally in wei to avoid the rounding errors a smaller number of decimal places could introduce.