Block size is the amount of data contained in a particular block. Depending on the protocol, it may be measured directly in bytes or controlled through another protocol-specific metric.

A block contains both user transactions and metadata required by the protocol. A larger permitted block can potentially contain more transactions during each block interval.

Block-size limits

Larger blocks require nodes to transmit, validate, and store more data. Block-size limits therefore involve a trade-off between transaction capacity and the hardware and network requirements imposed on participants.

Some blockchains use a separate block weight metric instead of relying only on raw byte size.