<p>1 MB was the maximum Bitcoin block size until 2017, not the size of each block. In the early years there were few transactions and most blocks were almost empty.</p>
<p>After the august 2017 segwit soft fork, the way how the transactions size are measured and the maximum space available has changed, now blocks can be bigger than 1 MB.
If you are interested, you can find here how the things works now: <a href="https://en.bitcoin.it/wiki/Weight_units" rel="nofollow noreferrer">https://en.bitcoin.it/wiki/Weight_units</a></p>
<p>This is the historical chart of Bitcoin average block size</p>
<p><a href="https://i.sstatic.net/8tNFg.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/8tNFg.png" alt="enter image description here" /></a></p>
<p>currently the average block size is about 1.33 MB
<br><br></p>
<p>Edit: I have updated my answer to take into account the changes introduced with segwit soft fork.</p>

CC BY-SA 4.0
2021-04-21T14:45:23.053Z
I corrected the answer, thanks
leevancleef
CC BY-SA 4.0
2021-04-21T22:18:48.680Z
modified, I hope it goes well now :)
leevancleef
CC BY-SA 4.0
2021-04-21T10:42:55.837Z
2021-04-21T22:20:10.007Z
2021-04-21T22:20:10.007Z
leevancleef
<p>There are approximately 700,000 blocks as of March 2021 [<a href="https://www.blockchain.com/btc/blocks" rel="nofollow noreferrer">1</a>]. How comes the blockchain size is only ~350 GB [<a href="https://www.blockchain.com/charts/blocks-size" rel="nofollow noreferrer">2</a>] and not 700 GB given that the block size is 1 MB?</p>
<p>Thank you for your help.</p>

CC BY-SA 4.0
2021-04-21T21:37:20.747Z
The block size is not 1MB, It is 4 weight units (which can be comprised of up to about 4MB of data). This change came into effect in 2017, so the upper bound of the possible blockchain size is actually larger than OP suggests.
chytrik
<blockchain><blocksize>
Discrepancy in the blockchain size
JacopoStanchi
# Discrepancy in the blockchain size

(Asked by: username_0 on 2021-04-21)

There are approximately 700,000 blocks as of March 2021 [[1](https://www.blockchain.com/btc/blocks)]. How comes the blockchain size is only ~350 GB [[2](https://www.blockchain.com/charts/blocks-size)] and not 700 GB given that the block size is 1 MB?

Thank you for your help.

**Tags:** blockchain, blocksize

> **Comments:**
> **username_1**: The block size is not 1MB, It is 4 weight units (which can be comprised of up to about 4MB of data). This change came into effect in 2017, so the upper bound of the possible blockchain size is actually larger than OP suggests.  

---

## 1 answers

### Answer by username_2 on 2021-04-21. Score: 4 | Accepted answer

1 MB was the maximum Bitcoin block size until 2017, not the size of each block. In the early years there were few transactions and most blocks were almost empty.

After the august 2017 segwit soft fork, the way how the transactions size are measured and the maximum space available has changed, now blocks can be bigger than 1 MB.
If you are interested, you can find here how the things works now: <https://en.bitcoin.it/wiki/Weight_units>

This is the historical chart of Bitcoin average block size

[![enter image description here](https://i.sstatic.net/8tNFg.png)](https://i.sstatic.net/8tNFg.png)

currently the average block size is about 1.33 MB

Edit: I have updated my answer to take into account the changes introduced with segwit soft fork.

> **Comments:**
> **username_2**: I corrected the answer, thanks  
> **username_2**: modified, I hope it goes well now :)  

---

