<p>First of all, actual difficulty is defined as the number <code>d</code> such that the probability of a random hash being valid is <code>1/(d*2^32)</code>. In other words, the hash needs to have at least <code>32 + log_2(d)</code> zeros in front of it to be valid. (This is not exactly the case if <code>d</code> is not a power of 2, but you get the general idea.)</p>

<p>In that article, a difficulty of <code>2^-12</code> means that the probability of a random share being valid is <code>1/(2^-12 * 2^32) = 2^-20</code>. Note that typically, pool difficulty, is measured in multiples of <code>2^-16</code> for reasons discussed in the article, so a difficulty of <code>2^-12</code> would be a pool difficulty of <code>2^4 = 16</code>.</p>

CC BY-SA 3.0
2014-03-27T23:22:12.500Z
2014-03-27T23:22:12.500Z
Tony
<p>These figures represent the difficulty at which the respective mining pool accepts a hash as a <em>share</em> of the mining pool's work. <strong>The actual network difficulty cannot be calculated from these figures.</strong></p>

<p><strong>Explanation:</strong>
While Bitcoin uses <code>SHA256</code> as the hashing algorithm, Litecoin uses <code>Scrypt</code> which is much more complex.</p>

<p>Therefore, a Litecoin difficulty of 1 represented a much greater amount of work than a Bitcoin difficulty of 1. If Litecoin mining pool operators would have accepted only hashes that fulfilled a difficulty of 1 or greater as valid <em>shares</em>, they would have only accepted valid blocks as <em>shares</em>, essentially reducing their contributors to solo miners. In order to estimate the work done by their contributers, they allowed hashes that fulfilled a much lower difficulty as <em>shares</em>, as seen in the linked website.</p>

CC BY-SA 3.0
2013-12-27T21:37:56.013Z
2013-12-27T21:37:56.013Z
Murch
<p>In the following list I always see difficulty values like 2^-12
How to calculate the actual difficulty from it?</p>

<p><a href="https://github.com/litecoin-project/litecoin/wiki/Comparison-of-mining-pools" rel="nofollow">Comparison of mining pools</a></p>

<litecoin><difficulty>
Litecoin - how to calculate the difficulty from 2^-N
Aley
# Litecoin - how to calculate the difficulty from 2^-N

(Asked by: username_0 on 2013-05-10)

In the following list I always see difficulty values like 2^-12
How to calculate the actual difficulty from it?

[Comparison of mining pools](https://github.com/litecoin-project/litecoin/wiki/Comparison-of-mining-pools)

**Tags:** litecoin, difficulty


---

## 2 answers

### Answer by username_1 on 2014-03-27. Score: 1

First of all, actual difficulty is defined as the number `d` such that the probability of a random hash being valid is `1/(d*2^32)`. In other words, the hash needs to have at least `32 + log_2(d)` zeros in front of it to be valid. (This is not exactly the case if `d` is not a power of 2, but you get the general idea.)

In that article, a difficulty of `2^-12` means that the probability of a random share being valid is `1/(2^-12 * 2^32) = 2^-20`. Note that typically, pool difficulty, is measured in multiples of `2^-16` for reasons discussed in the article, so a difficulty of `2^-12` would be a pool difficulty of `2^4 = 16`.


---

### Answer by username_2 on 2013-12-27. Score: 0

These figures represent the difficulty at which the respective mining pool accepts a hash as a *share* of the mining pool's work. **The actual network difficulty cannot be calculated from these figures.**

**Explanation:**
While Bitcoin uses `SHA256` as the hashing algorithm, Litecoin uses `Scrypt` which is much more complex.

Therefore, a Litecoin difficulty of 1 represented a much greater amount of work than a Bitcoin difficulty of 1. If Litecoin mining pool operators would have accepted only hashes that fulfilled a difficulty of 1 or greater as valid *shares*, they would have only accepted valid blocks as *shares*, essentially reducing their contributors to solo miners. In order to estimate the work done by their contributers, they allowed hashes that fulfilled a much lower difficulty as *shares*, as seen in the linked website.


---

