Gas Fees
In simple terms
Gas fees are charges you pay whenever you perform an action on a blockchain, like sending cryptocurrency or using a smart contract. Think of it like paying a small fee to use a vending machine—the blockchain needs to be compensated for processing your transaction.
Definition
Transaction fees required to use a blockchain.
In depth
Gas fees represent the computational cost required for validators to execute and verify transactions on a blockchain network. Each operation (transfer, contract execution, state change) consumes a specific amount of 'gas,' priced in the network's native currency, which incentivizes validators to include your transaction in the next block. The total fee is calculated as: gas used × gas price per unit. During periods of high network congestion, users must bid higher gas prices to prioritize their transactions, while simple transfers consume less gas than complex smart contract interactions.
How does Gas Fees work?
On Ethereum and similar networks every operation a transaction performs costs a set number of gas units: a plain transfer costs 21,000, while contract interactions cost more. Since EIP-1559 the protocol sets a base fee per unit of gas that rises when blocks are full and falls when they are not, and that base fee is burned. Senders add a priority fee that goes to the validator including the transaction. The total charge is gas used multiplied by base plus priority fee. A transaction that fails still consumes the gas it used.
An example
Someone sends a token transfer that consumes 65,000 gas units. The base fee is 20 gwei and they add a 2 gwei priority fee, so the cost is 65,000 multiplied by 22 gwei, or 0.00143 ETH. The identical transfer during heavy congestion, at a 100 gwei base fee, would cost 0.00663 ETH. These gas prices are illustrative.
Figures are illustrative only.
What beginners get wrong
- Setting a gas limit too low, so the transaction runs out of gas, fails, and the fee for work already done is not returned.
- A failed transaction still costs money, because network fees pay for the computation attempted even when nothing transfers.
- Sending a small amount across a congested network when the fee exceeds the transfer itself; checking current fees first avoids this.
- Forgetting that a wallet needs the native coin for gas, so tokens can sit stranded in an account holding no ETH.
Related terms
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Educational only — not financial advice.