What unit equals one-billionth of an ether?

What unit equals one-billionth of an ether? Gwei equals one-billionth of an ether, or 0.000000001 ETH.

The name is short for gigawei: “giga” denotes one billion, while wei is Ethereum’s smallest accounting unit. Since one ether contains 10^18 wei, one gwei contains 10^9 wei. Ethereum records balances internally in wei, even though wallets and explorers usually display larger denominations for readability.

Gwei is most familiar from transaction fees. Ethereum gas prices are commonly quoted in gwei, such as 20 gwei or 50 gwei, rather than in fractions of an ETH. The total fee depends on the gas price and the amount of gas a transaction uses. Under Ethereum’s fee system, the base fee is burned and an optional priority fee, or tip, goes to the validator.

A common mix-up is confusing gwei with wei, finney, or szabo. Wei is smaller; finney and szabo are larger ether denominations. Gwei is the convenient middle unit used for gas prices.