Gas Station

Every block has a base fee which acts as a reserve price. To be eligible for inclusion in a block the offered price per gas must at least equal the base fee. The base fee is calculated independently of the current block and is instead determined by the blocks before it - making transaction fees more predictable for users. When the block is created this base fee is "burned", removing it from circulation.

The base fee is calculated by a formula that compares the size of the previous block (the amount of gas used for all the transactions) with the target size. The base fee will increase by a maximum of 12.5% per block if the target block size is exceeded. This exponential growth makes it economically non-viable for block size to remain high indefinitely.

Block Number	Included Gas	Fee Increase	Current Base Fee
1	15M	0%	100 gwei
2	30M	0%	100 gwei
3	30M	12.5%	112.5 gwei
4	30M	12.5%	126.6 gwei
5	30M	12.5%	142.4 gwei
6	30M	12.5%	160.2 gwei
7	30M	12.5%	180.2 gwei
8	30M	12.5%	202.7 gwei

Following the table above - to create a transaction on block number 9, a wallet will let the user know with certainty that the maximum base fee to be added to the next block is current base fee * 112.5% or 202.7 gwei * 112.5% = 228.1 gwei.

It's also important to note it is unlikely we will see extended spikes of full blocks because of the speed at which the base fee increases preceding a full block.

Block Number	Included Gas	Fee Increase	Current Base Fee
30	30M	12.5%	2705.6 gwei
...	...	12.5%	...
50	30M	12.5%	28531.3 gwei
...	...	12.5%	...
100	30M	12.5%	10302608.6 gwei