Glossary
Gas Limit
The maximum gas a transaction may consume, or that all transactions in a block may collectively consume — a ceiling that caps computation and, for senders, the fee they can pay.
A gas limit exists at two levels. Per transaction, the sender sets the maximum units of gas the execution may use; if the work exceeds it, the transaction reverts but the gas already spent is still charged. Set it too low and the transaction fails, too high and only the gas actually consumed is billed.
Per block, the protocol enforces a collective ceiling — around 30 million gas on Ethereum — that bounds how much computation each block can contain. Under EIP-1559 the base fee rises when blocks run consistently above the target, which is half of that block limit.