Block Fees

What this measures

This chart tracks the average amount of transaction fees collected in each block, in BTC, based on mempool.space data. It counts fees only: the subsidy, the newly created bitcoin attached to every block, is left out. Fees are the price users pay to get a seat in a block. Since those seats are limited, the price follows demand.

How to read block fees

A transaction’s fee does not depend on the amount sent, but on the space it takes up. Miners sort transactions by fee rate, in satoshis per vbyte (sat/vB), and fill the block starting with the best-paying ones. The total in a block therefore depends on 2 things: the level of fee rates, broken down in the median fee rate, and how many transactions are willing to pay that price.

The chart shows an average per period, not every single block. That smooths things out, but isolated cases can still pull it around: a transaction sent by mistake with an absurd fee, or, the other way, near-empty blocks. The figure is also in BTC: fees that look stable in bitcoin can mean a very different bill in dollars depending on the price.

Finally, not everything happens on-chain. Some acceleration services run by pools charge for including a transaction outside the transaction itself. Those payments never show up in the block’s visible fees.

A market that moves in waves

Outside of busy periods, fees weigh little. The spikes line up with clearly identified waves of demand. In late 2017, speculation filled blocks to the brim. In spring 2023, Ordinals inscriptions and BRC-20 tokens pushed fees up for weeks. In April 2024, the launch of Runes at block 840,000, the halving block, produced a block whose fees far exceeded the new 3.125 BTC subsidy.

🪙 What are Ordinals, Runes, and other inscriptions on Bitcoin?

These episodes show that demand for block space does not come from payments alone. Many of the fee records were driven by uses that have nothing to do with money, and whose value divides the community. Mempool size shows how long the wait lasted at the time. And once each wave passed, fees have so far gone back to being a minor share of miner revenue.

In this auction, someone who simply wants to withdraw their coins from an exchange into self-custody pays the same rate as someone inscribing an image, and no rule caps that rate.