Gas

Every operation performed on the Ethereum Virtual Machine, from a simple ETH transfer to a complex smart contract call, consumes a measured amount of computational effort. Gas is the unit that quantifies that effort: each low-level operation (a storage write, an arithmetic step, a contract deployment) has a fixed gas cost written into the protocol, and the total gas a transaction uses is multiplied by the current gas price to determine the fee actually paid.

Since the 2021 London upgrade introduced EIP-1559, that price has split into two parts. A base fee is set automatically by the protocol depending on how full the previous block was, rising when demand is high and falling when it is quiet, and it is burned rather than paid to anyone. On top of it, a user can add a priority fee, a tip that goes to the validator proposing the block and pushes the transaction ahead of others during congestion. Both are usually denominated in gwei, a billionth of an ether.

Two separate limits protect the network from abuse. A user sets a gas limit on each transaction, the maximum gas they are willing to spend; set it too low and the transaction fails with an "out of gas" error, with the fee for the work already done still lost. The network also enforces a block-wide gas limit capping total computation per block; validators raised this ceiling from 30 million to 60 million gas during 2025, with further increases planned as later upgrades roll out.

Because most everyday activity has shifted to Ethereum layer-2 networks such as Arbitrum, Optimism, and Base, typical gas costs in 2026 run to a fraction of a cent, far below the multi-dollar fees seen during past congestion spikes on the base layer.