Gas Fee

What a gas fee is

A gas fee is the transaction fee paid by a user of a blockchain — particularly Ethereum and EVM-compatible networks — to process a transaction or execute a smart contract. It compensates validators (under proof of stake) or miners (under proof of work) for the computation and storage they provide and at the same time makes spamming the network economically unattractive.

The term "gas" describes an abstract unit of computation and storage: every operation on the Ethereum Virtual Machine (EVM) consumes a defined amount of gas. A simple ETH transfer costs 21,000 gas, for example, while a complex DEX swap can consume 200,000 to 500,000 gas.

EIP-1559 and today's pricing

Until August 2021 Ethereum's fee system was purely auction-based: the highest gas bid won inclusion. The result was chaotic fee spikes — during the 2021 NFT boom users paid up to USD 200 for a single swap.

The EIP-1559 upgrade rebuilt the system fundamentally. Today's fee has two components:

• Base fee: algorithmically computed minimum price per gas unit, automatically adjusted to network demand. Permanently destroyed ("burned") — this burn mechanism turns ETH deflationary during periods of intense activity.
• Priority fee (tip): optional tip to the validator for faster inclusion ("maximum priority fee per gas").

The effective fee works out to: gas used × (base fee + priority fee), measured in gwei (billionths of an ETH).

Current orders of magnitude (2026)

Typical costs on Ethereum mainnet in mid-2026:

• Simple ETH transfer: USD 1 to 5
• ERC-20 token transfer: USD 2 to 10
• DEX swap (Uniswap, Curve): USD 5 to 50
• NFT mint or complex DeFi action: USD 10 to 100

In peak-load periods (NFT drops, market turmoil), these levels can rise 5 to 10 times.

Layer-2 networks such as Arbitrum, Optimism, Base and zkSync cut these costs dramatically — typically to USD 0.05 to 0.50 per transaction. Since the Dencun upgrade of March 2024 ("proto-danksharding"), layer-2 fees have fallen by a further 90%, which is what has finally unlocked decentralised applications for the mass market.

Practical consequences

For retail investors, gas fees have two practical implications. First, small transactions on mainnet barely make sense economically — paying USD 20 in fees to swap USD 50 of tokens means giving up 40% before the first price move. Second, the choice of blockchain matters: anyone trading regularly should use layer-2 networks or alternative layer-1 chains (Solana, BNB).

For tax purposes, the Austrian tax authority generally treats gas fees as acquisition or disposal-related costs — they therefore reduce taxable gains. For active DEX traders this can make a significant difference, but it requires gap-free transaction records.

What investors often ask

How can I estimate a gas fee before sending a transaction? Wallet apps such as MetaMask display the estimated gas price live, supplemented by sites like etherscan.io/gastracker.