Block size limitBitcoin Cash adaptive blocksize limit algorithm (ABLA)
The limit is calculated for every block from the sizes of the blocks before it. It never falls below 32 MB.
Limit for the current block
No data yet. The limit is shown as soon as the node has been read.
Limit and real block sizes
Bars are drawn to the same scale. Limit and floor are consensus values; block sizes are measured.
Block sizes, last 144 blocks
No block data yet.
Questions
What is ABLA?
The Adaptive Blocksize Limit Algorithm, active on Bitcoin Cash since the May 2024 upgrade. Instead of a fixed number, every block carries a limit that is calculated from the sizes of the blocks before it.
Can the limit fall below 32 MB?
No. 32 MB is the floor. The algorithm can only raise the limit above it when blocks are consistently large, and lets it sink back toward 32 MB when they are small.
Why is the limit 32 MB when blocks are much smaller?
The limit is a ceiling, not a target. Blocks contain the transactions that were actually sent. As long as usage stays far below the floor, the limit stays at the floor.
Where do these numbers come from?
From a Bitcoin Cash Node: each block header it reports carries the algorithm's state (block size, control size, elastic buffer, the limit and the limit for the next block).