<p>Hash Rate
The hash rate is the measuring unit of the processing power of the Bitcoin network. The Bitcoin network must make intensive mathematical operations for security purposes. When the network reached a hash rate of 10 Th/s, it meant it could make 10 trillion calculations per second. <a href="https://bitcoin.org/en/vocabulary#hash-rate" rel="nofollow noreferrer">Source</a></p>

CC BY-SA 4.0
2019-09-07T18:55:12.407Z
This might be useful to others but doesn't give me the information I was looking for with my question... please define "calculation" to answer the detail of my question.
Bradley Thomas
CC BY-SA 4.0
2019-09-07T19:10:35.673Z
The hash rate is literally how many distinct block header hashes you can try per second. [Source](https://bitcoin.stackexchange.com/a/84929/98065)
yahiheb
CC BY-SA 4.0
2019-09-07T18:54:20.610Z
2019-09-07T18:54:20.610Z
yahiheb
<p>The number reported is an <em>estimation</em> of the number of block headers iterated through by all miners on the network.</p>

<p>This means it refers to double-SHA256 hashes performed, not broken down to individual SHA256 operations. This makes the most sense, because even in the very early days (2010, perhaps before), no full SHA256 instances were being computed. Several optimizations let you skip parts of the computation.</p>

<p>It is an approximation, because the actual hash rate is not observable. It can be computed by looking at the created blocks on the network, and treating each as (2^256 / target) worth of attempts (so approximately 4.3 billion hashes per difficulty per block). That is the expected number of necessary hashes.</p>

<p>By looking at the blocks, another inaccuracy is introduced: only blocks that end up in the main chain are counted. Some blocks end up on temporary forks because another miner produces another nearly simultaneous competing block that wins. This is only a fraction of a percent today, but it does waste a small amount of hashrate, which also ends up not being counted.</p>

CC BY-SA 4.0
2019-09-07T19:42:37.950Z
2019-09-07T19:42:37.950Z
Pieter Wuille
<p>Specifically, does it refer to SHA hashes per second, or does it refer to nonce-iterations per second, because to check a nonce requires the application of SHA twice.</p>

CC BY-SA 4.0
2019-09-07T18:53:32.190Z
Double SHA256's per second.
MCCCS
<hashpower>
What precisely does the commonly reported network hash rate refer to?
Bradley Thomas
# What precisely does the commonly reported network hash rate refer to?

(Asked by: username_0 on 2019-09-07)

Specifically, does it refer to SHA hashes per second, or does it refer to nonce-iterations per second, because to check a nonce requires the application of SHA twice.

**Tags:** hashpower

> **Comments:**
> **username_1**: Double SHA256's per second.  

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## 2 answers

### Answer by username_3 on 2019-09-07. Score: 7 | Accepted answer

The number reported is an *estimation* of the number of block headers iterated through by all miners on the network.

This means it refers to double-SHA256 hashes performed, not broken down to individual SHA256 operations. This makes the most sense, because even in the very early days (2010, perhaps before), no full SHA256 instances were being computed. Several optimizations let you skip parts of the computation.

It is an approximation, because the actual hash rate is not observable. It can be computed by looking at the created blocks on the network, and treating each as (2^256 / target) worth of attempts (so approximately 4.3 billion hashes per difficulty per block). That is the expected number of necessary hashes.

By looking at the blocks, another inaccuracy is introduced: only blocks that end up in the main chain are counted. Some blocks end up on temporary forks because another miner produces another nearly simultaneous competing block that wins. This is only a fraction of a percent today, but it does waste a small amount of hashrate, which also ends up not being counted.


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### Answer by username_2 on 2019-09-07. Score: 0

Hash Rate
The hash rate is the measuring unit of the processing power of the Bitcoin network. The Bitcoin network must make intensive mathematical operations for security purposes. When the network reached a hash rate of 10 Th/s, it meant it could make 10 trillion calculations per second. [Source](https://bitcoin.org/en/vocabulary#hash-rate)

> **Comments:**
> **username_0**: This might be useful to others but doesn't give me the information I was looking for with my question... please define "calculation" to answer the detail of my question.  
> **username_2**: The hash rate is literally how many distinct block header hashes you can try per second. [Source](https://bitcoin.stackexchange.com/a/84929/98065)  

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