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Block size

(also block size limit)

Block size definition

Block size pertains to the largest quantity of data that a single block can accommodate in a blockchain. Within the realm of cryptocurrencies such as Bitcoin, block size establishes the capacity for transactions that can be processed and incorporated within a block. The block size cap has been a subject of debate among the crypto community because it has a direct impact on network scalability, the speed of transactions, and the associated fees.

Block size examples

  • Bitcoin: Initially, the Bitcoin block size limit was set at 1 MB, which allowed for approximately 2,000 to 4,000 transactions per block, depending on the size of individual transactions.
  • Bitcoin Cash: In 2017, Bitcoin Cash forked from Bitcoin and increased its block size limit to 32 MB, aiming to improve transaction throughput and reduce fees.

Block size considerations


  • Larger block sizes can accommodate more transactions, leading to faster processing times and lower fees.
  • Increasing the block size limit can help a cryptocurrency network scale and handle a growing number of transactions.


  • Larger block sizes can lead to increased centralization because they require more powerful hardware and greater bandwidth to process, which can price out smaller miners.
  • Bigger blocks can result in longer blockchain synchronization times, consuming more storage and resources.

Tips for choosing a cryptocurrency with the right block size

  • Assess the trade-offs between transaction speed, fees, and decentralization.
  • Consider the scalability of the network and its ability to handle future transaction growth.
  • Evaluate the development team's approach to addressing block size and scalability issues.