<p>Yes, it's almost always necessary.  The current Bitcoin difficulty is 48,807,487,245, which means (approximately) that if you go through all possible values for the regular 32-bit nonce, your probability of finding a valid proof of work is only 1 in 48,807,487,245.  So the vast majority of times, you will exhaust all possibilities for the regular nonce, at which point you can increment the extraNonce and continue.</p>

CC BY-SA 3.0
2015-05-18T19:23:46.477Z
2015-05-18T19:23:46.477Z
Nate Eldredge
<p>Is extranonce ever necessary to find a block, e.g., in cases where exhausting the regular nonce range fails to block? Is this the rationale behind extranonce?</p>

CC BY-SA 3.0
2015-05-19T08:20:45.400Z
I don't think "blocking" is a term ever used for "creating blocks".
Jannes
CC BY-SA 3.0
2015-05-20T04:17:20.987Z
@Jannes I've seen it used that way before, but I don't know how established that terminology is.
Geremia
<nonce>
Is extranonce sometimes necessary for blocking?
Geremia
# Is extranonce sometimes necessary for blocking?

(Asked by: username_0 on 2015-05-18)

Is extranonce ever necessary to find a block, e.g., in cases where exhausting the regular nonce range fails to block? Is this the rationale behind extranonce?

**Tags:** nonce

> **Comments:**
> **username_1**: I don't think "blocking" is a term ever used for "creating blocks".  
> **username_0**: @username_1 I've seen it used that way before, but I don't know how established that terminology is.  

---

## 1 answers

### Answer by username_2 on 2015-05-18. Score: 1 | Accepted answer

Yes, it's almost always necessary. The current Bitcoin difficulty is 48,807,487,245, which means (approximately) that if you go through all possible values for the regular 32-bit nonce, your probability of finding a valid proof of work is only 1 in 48,807,487,245. So the vast majority of times, you will exhaust all possibilities for the regular nonce, at which point you can increment the extraNonce and continue.


---

