<p>10 minutes is the average time between blocks that the network tries to attain (by adjusting the target/difficulty).  It is not a fixed thing.</p>

<p>Due to the way mining works, there is a great deal of random variation in the time between blocks.  A block may be found seconds after the last one or hours may go by between blocks.</p>

CC BY-SA 3.0
2013-11-12T23:38:28.260Z
2013-11-12T23:38:28.260Z
Compro01
<p>There are a few things to know about the frequency of blocks:</p>

<ol>
<li><p>Every hash has the same chance of finding a block. So, times between blocks are randomly distributed.</p></li>
<li><p>The difficulty (i.e. the expected number of hashes required to find the next block) is only adjusted every 2016 blocks. With ten minutes between blocks that would be every 14 days. However, since a lot of hashing power is being added to the network every day, the hashing power quickly starts to exceed the difficulty that it was estimated to accomodate, and the average time between blocks starts to get lower until the difficulty is adjusted again. So right now, we are probably closer to a block every 7 minutes in average than every 10 minutes.</p></li>
</ol>

CC BY-SA 3.0
2013-11-12T23:46:27.320Z
2013-11-12T23:46:27.320Z
Murch
<p>A new block will be created in approximately 10 minutes, but I saw on blockchain.info that these two blocks were found only two minutes apart!</p>

<p><img src="https://i.sstatic.net/Zl08g.png" alt="enter image description here"></p>

<p>How come that the time between the first two listed blocks is just two minutes?</p>

CC BY-SA 3.0
2013-11-12T23:47:22.557Z
See also this related question: [What is the expected time until the next block is found?](http://bitcoin.stackexchange.com/questions/3909/what-is-the-expected-time-until-the-next-block-is-found?rq=1)
Murch
<block><difficulty><block-interval>
Why was the time between these two blocks not approximately 10 minutes?
kakahong
# Why was the time between these two blocks not approximately 10 minutes?

(Asked by: username_0 on 2013-11-12)

A new block will be created in approximately 10 minutes, but I saw on blockchain.info that these two blocks were found only two minutes apart!

![enter image description here](https://i.sstatic.net/Zl08g.png)

How come that the time between the first two listed blocks is just two minutes?

**Tags:** block, difficulty, block-interval

> **Comments:**
> **username_1**: See also this related question: [What is the expected time until the next block is found?](http://bitcoin.stackexchange.com/questions/3909/what-is-the-expected-time-until-the-next-block-is-found?rq=1)  

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## 2 answers

### Answer by username_1 on 2013-11-12. Score: 4 | Accepted answer

There are a few things to know about the frequency of blocks:

1. Every hash has the same chance of finding a block. So, times between blocks are randomly distributed.
2. The difficulty (i.e. the expected number of hashes required to find the next block) is only adjusted every 2016 blocks. With ten minutes between blocks that would be every 14 days. However, since a lot of hashing power is being added to the network every day, the hashing power quickly starts to exceed the difficulty that it was estimated to accomodate, and the average time between blocks starts to get lower until the difficulty is adjusted again. So right now, we are probably closer to a block every 7 minutes in average than every 10 minutes.


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### Answer by username_2 on 2013-11-12. Score: 3

10 minutes is the average time between blocks that the network tries to attain (by adjusting the target/difficulty). It is not a fixed thing.

Due to the way mining works, there is a great deal of random variation in the time between blocks. A block may be found seconds after the last one or hours may go by between blocks.


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