Wei and Gwei

Wei is the smallest indivisible unit of ether, and gwei is one billion wei, the unit conventionally used to quote gas prices.

Ether is denominated in integer units to avoid floating-point errors. One ether equals 10^18 wei, the smallest unit, and one gwei equals 10^9 wei. Onchain values, balances, and fees are all stored and computed as integer wei. Gas prices are quoted in gwei because it is a readable scale for typical fees. Converting between wei, gwei, and ether is a routine source of bugs. Our decoded transaction data returns amounts as exact integer wei alongside gwei-scaled gas prices, so you avoid precision loss when computing values.