What is a Bitcoin block?

13 Feb 2015

Bitcoin Wood BlockA Bitcoin block contains a set of data that holds all the information necessary to verify transaction and link the block back to its previous block in the chain.

The constituent parts of a block can be seen in the table below.

The block size is simply the size of the block in bytes – this varies mainly depending on the number of transactions.

The block data is shown in the table below:

 block header data


The block header is the list of meta-data about the block – a full explanation can be seen in our guide – What is a block header in Bitcoin? – the block header is an 80 byte field. The next pieces of information are the number of transactions in the block and the transactions themselves.

A transaction is usually above 250 bytes depending on its type – multisignature transactions use a lot more space due to the required conditions on spending – you can see more about the different transaction types here. The average block contains about 500 transactions – which equates to just less than one transaction per second.


Important information

This website is only provided for your general information and is not intended to be relied upon by you in making any investment decisions. You should always combine multiple sources of information and analysis before making an investment and seek independent expert financial advice.

Where we list or describe different products and services, we try to give you the information you need to help you compare them and choose the right product or service for you. We may also have tips and more information to help you compare providers.

Some providers pay us for advertisements or promotions on our website or in emails we may send you. Any commercial agreement we have in place with a provider does not affect how we describe them or their products and services. Sponsored companies are clearly labelled.

CryptoCompare needs a newer browser in order to work.
Please use one of the browsers below: