---
title: "What are Ethereum gas fees and why do they change?"
url: "https://worldwiki.io/q/what-are-ethereum-gas-fees-and-why-do-they-change"
type: "question"
language: "en"
intent: "informational"
entity: "Ethereum"
topic: "Blockchain"
published: "2026-09-18 07:10:23"
updated: "2026-09-18 16:10:23"
---

# What are Ethereum gas fees and why do they change?

## Short answer

Gas measures the computation a transaction needs, and fees are paid in ETH, usually quoted in gwei (one-billionth of an ETH). Since EIP-1559 (the London upgrade, August 5, 2021), each fee has a base fee that is burned plus an optional tip to the validator. The base fee can move by up to 12.5% per block depending on demand, so fees rise when the network is busy.

## Answer

Many users move activity to layer-2 rollups, which usually charge lower fees than mainnet [6][4][11].

## Related questions

- [How much ETH do you need to stake on Ethereum?](https://worldwiki.io/q/how-much-eth-do-you-need-to-stake-on-ethereum)
- [What is the difference between Ethereum and Bitcoin?](https://worldwiki.io/q/what-is-the-difference-between-ethereum-and-bitcoin)
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- [Is Ethereum the same as ether (ETH)?](https://worldwiki.io/q/is-ethereum-the-same-as-ether-eth)

## Sources

1. [What is Ethereum? (A Complete Guide)](https://ethereum.org/what-is-ethereum/) — ethereum.org · evidence page: https://worldwiki.io/source/196
2. [Introduction to smart contracts](https://ethereum.org/developers/docs/smart-contracts/) — ethereum.org · evidence page: https://worldwiki.io/source/197
3. [What is Ether (ETH)?](https://ethereum.org/what-is-ether/) — ethereum.org · evidence page: https://worldwiki.io/source/198
4. [Timeline of all Ethereum forks (2014 to present)](https://ethereum.org/ethereum-forks/) — ethereum.org · evidence page: https://worldwiki.io/source/186
5. [Ethereum Virtual Machine (EVM)](https://ethereum.org/developers/docs/evm/) — ethereum.org · evidence page: https://worldwiki.io/source/199
6. [Gas and fees](https://ethereum.org/developers/docs/gas/) — ethereum.org · evidence page: https://worldwiki.io/source/200
7. [Proof-of-stake (PoS)](https://ethereum.org/developers/docs/consensus-mechanisms/pos/) — ethereum.org · evidence page: https://worldwiki.io/source/161
8. [Prague-Electra (Pectra)](https://ethereum.org/roadmap/pectra/) — ethereum.org · evidence page: https://worldwiki.io/source/201
9. [The Merge](https://ethereum.org/roadmap/merge/) — ethereum.org · evidence page: https://worldwiki.io/source/160
10. [Ethereum Activates Fusaka Upgrade, Aiming to Cut Node Costs, Speed Layer-2 Settlements](https://www.coindesk.com/tech/2025/12/03/ethereum-activates-fusaka-upgrade-aiming-to-cut-node-costs-speed-layer-2-settlements) — CoinDesk · evidence page: https://worldwiki.io/source/202
11. [Layer 2](https://ethereum.org/layer-2/) — ethereum.org · evidence page: https://worldwiki.io/source/203
12. [Client diversity](https://ethereum.org/developers/docs/nodes-and-clients/client-diversity/) — ethereum.org · evidence page: https://worldwiki.io/source/191