What are the base fee and the priority fee on Ethereum?
The base fee is a price per unit of gas that the network sets for each block, and it is burned.1,2 The priority fee, or tip, goes to the validator, and your max fee caps what you pay per unit.1
Two prices since August 2021
Ethereum's London upgrade, on 5 August 2021, changed how fees work through EIP-1559.3 Before, fees worked like a simple auction. Now the price per unit of gas has two parts: a base fee and a tip.3,1
The base fee
Every block has a base fee. It acts like a reserve price: to get into the block, you must offer at least this much per unit of gas.1
You don't choose it. The network works it out from the blocks before, which makes fees easier to predict.1 Each block has a target size of half its gas limit.1 If the last block was above target, the base fee goes up. If it was below, the base fee goes down.1,2
The change is at most 12.5% per block.1 A full block raises the base fee by 12.5%, and an empty block lowers it by 12.5%.1 Prices can change every twelve seconds.4
The base fee is burned. It is destroyed, and nobody receives it.2,4
If the base fee is 40 gwei and the block is full, the next base fee is 40 × 1.125 = 45 gwei. If the block is empty, it is 40 × 0.875 = 35 gwei.
The priority fee (tip)
The priority fee, or tip, is an extra amount for the validator who includes your transaction.1,4 A transaction that pays only the base fee is valid, but unlikely to be picked. It gives validators no reason to choose it.1
When the network is busy, people raise their tips to get ahead of others.1
The max fee
You also set a max fee: the most you will pay per unit of gas, base fee and tip included.5 You pay the block's base fee plus your tip, as long as the two together fit under your max fee.2 If they don't fit, your tip is cut, because the base fee is paid first.2
You never pay more than the base fee plus the tip.2 ethereum.org says the difference between your max fee and that amount is refunded.1 Before a transaction runs, your account must hold enough ETH to cover the amount you send plus the gas limit times the max fee.2
- Burned = gas used × base fee.
- To the validator = gas used × tip.
- Never charged = gas used × (max fee − base fee − tip).
How an explorer shows it
Here is a real token transfer from December 2021, as Etherscan shows it.6
| What Etherscan shows | Value |
|---|---|
| Gas limit and gas used | 41,754 limit, 34,795 used6 |
| Base, Max and Max Priority | 107.275194209, 137.431755093 and 2 gwei6 |
| Transaction Fee | 0.003802230382502155 ETH6 |
| Burnt | 0.003732640382502155 ETH6 |
| Txn Savings | 0.00097970753595878 ETH6 |
The numbers fit the formulas above. The fee is the 34,795 gas used times 109.275194209 gwei, which is the base fee plus the 2 gwei tip.6 "Burnt" is the gas used times the base fee. "Txn Savings" is the part of the max fee that was never charged.6
- Gas and fees. ethereum.org developer docs, page updated 24 June 2026.
- EIP-1559: Fee market change for ETH 1.0 chain. Ethereum Improvement Proposals (Vitalik Buterin and others), created 13 April 2019, status Final.
- What is Gas Fee?. Etherscan Information Center (Kaven Choi), 26 November 2019, updated 21 June 2026.
- Gas fees. ethereum.org, page updated 8 April 2025.
- Transactions. ethereum.org developer docs, page updated 7 October 2026.
- Transaction details page for a token transfer, 6 December 2021 (tx 0x4f5ef12b…9de4). Etherscan, transaction of 6 December 2021, page read 22 October 2026.
General education built from the publicly available sources listed above. Not financial, legal, tax or investment advice. Naming a company, project or regulator is not an endorsement either way. Last checked 2026-10-22. Terms and disclaimer.