<p><strong>17</strong> judging by the latest blocks published on blockchain.info:
<a href="https://blockchain.info/block/0000000000000000057fcc708cf0130d95e27c5819203e9f967ac56e4df598ee" rel="noreferrer">https://blockchain.info/block/0000000000000000057fcc708cf0130d95e27c5819203e9f967ac56e4df598ee</a></p>

CC BY-SA 3.0
2017-01-18T01:23:50.487Z
Thanks especially for the link to make it easy to find out the answer in the future, as well.
sarnold
CC BY-SA 3.0
2017-11-18T12:38:50.533Z
The future is now ;-)  Changed to **18**, https://blockchain.info/pt/block/0000000000000000008be77e83deb352669b55fbe8f5ed208005fc1a9830c06c  (since Feb 2017 as [this block](https://blockchain.info/block/000000000000000000e907ebdb890c7f46c0649829b60e98ff5cb5e2b83fcc77), perhps before).
Peter Krauss
CC BY-SA 3.0
2017-11-18T14:16:25.870Z
An early block of  Mar' 2009 (block deep 6100) have  [8 zeros](https://blockchain.info/pt/block/00000000707f5eba0caca3b6e725956e92c62f68c114a239f49ca9cf2b043801)  (see same at [other explorer](https://blockexplorer.com/block/00000000707f5eba0caca3b6e725956e92c62f68c114a239f49ca9cf2b043801)).
Peter Krauss
CC BY-SA 4.0
2018-06-23T17:29:24.850Z
Still 18 zeros in June 2018
Paul Razvan Berg
CC BY-SA 4.0
2018-12-16T15:38:48.587Z
December 2018, 19 zeros
Konstantinos Kamaropoulos
CC BY-SA 3.0
2016-05-16T01:00:32.623Z
2016-05-16T01:00:32.623Z
derrend
<p>Clarifying: difficulty is a more human-friendly representation of the target. Tha target itself is not specified in terms of the amount of zeroes. This seemed to be the case with hashcash.</p>

<p>The more precise definition of the target is a maximum accepted number for the produced block hash. In this sense a certain hash with a certain number of leading zeroes may be accepted and another hash with the same amount of leading zeroes may not be accepted.</p>

CC BY-SA 3.0
2017-11-18T12:43:45.477Z
Hi Jonathas, we see that the  amount is growing, so, who (authority or Bitcoin-rule) define the amount?
Peter Krauss
CC BY-SA 3.0
2017-11-18T13:56:15.793Z
Hum... See [current difficulty](https://blockexplorer.com/api/status?q=getDifficulty) and [target concept](https://en.bitcoin.it/wiki/Target), this is the reference for number of zeros (!).
Peter Krauss
CC BY-SA 3.0
2016-05-16T15:20:06.340Z
2016-05-16T15:20:06.340Z
Jonathas Carrijo
<p>I'm trying to get my head around the difficulty setting of Bitcoin. 
How can I calculate how many zeros the target string needs to start with?</p>

<difficulty>
How many zeroes does the current target have?
Alice
# How many zeroes does the current target have?

(Asked by: username_0 on 2016-05-15)

I'm trying to get my head around the difficulty setting of Bitcoin.
How can I calculate how many zeros the target string needs to start with?

**Tags:** difficulty


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## 2 answers

### Answer by username_1 on 2016-05-16. Score: 11

**17** judging by the latest blocks published on blockchain.info:
<https://blockchain.info/block/0000000000000000057fcc708cf0130d95e27c5819203e9f967ac56e4df598ee>

> **Comments:**
> **username_2**: Thanks especially for the link to make it easy to find out the answer in the future, as well.  
> **username_3**: The future is now ;-)  Changed to **18**, https://blockchain.info/pt/block/0000000000000000008be77e83deb352669b55fbe8f5ed208005fc1a9830c06c  (since Feb 2017 as [this block](https://blockchain.info/block/000000000000000000e907ebdb890c7f46c0649829b60e98ff5cb5e2b83fcc77), perhps before).  
> **username_3**: An early block of  Mar' 2009 (block deep 6100) have  [8 zeros](https://blockchain.info/pt/block/00000000707f5eba0caca3b6e725956e92c62f68c114a239f49ca9cf2b043801)  (see same at [other explorer](https://blockexplorer.com/block/00000000707f5eba0caca3b6e725956e92c62f68c114a239f49ca9cf2b043801)).  
> **username_4**: Still 18 zeros in June 2018  
> **username_5**: December 2018, 19 zeros  

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### Answer by username_6 on 2016-05-16. Score: 3

Clarifying: difficulty is a more human-friendly representation of the target. Tha target itself is not specified in terms of the amount of zeroes. This seemed to be the case with hashcash.

The more precise definition of the target is a maximum accepted number for the produced block hash. In this sense a certain hash with a certain number of leading zeroes may be accepted and another hash with the same amount of leading zeroes may not be accepted.

> **Comments:**
> **username_3**: Hi Jonathas, we see that the  amount is growing, so, who (authority or Bitcoin-rule) define the amount?  
> **username_3**: Hum... See [current difficulty](https://blockexplorer.com/api/status?q=getDifficulty) and [target concept](https://en.bitcoin.it/wiki/Target), this is the reference for number of zeros (!).  

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