You can get any user's total karma from their profile. You can get the karma for each of their submissions from the submission's score, which is also public (and the conversion factor is 2:1, I think). Since submissions and comments are the only sources of karma, total comment karma is the difference. Then just divide by number of comments.

So the submission score is the sum of the “upvotes minus downvotes” — and not just the sum of upvotes?

Submissions cannot be downvoted.

Thanks, meaning the public karma of post is only upvotes and downvotes via flags (or any other negative ranking factor) are not applied to this count, right?

Aware of minimaxir‘s list — was there anything specific to that thread or his list that relates to topic of formula for calculating average karma per comment?

EDIT: Searched for “karma” on the linked HN thread and minimaxir GitHub page a did not find anything that would answer the question. Am I missing something?

No, I just gave a link to the list of features. Indeed, the karma for comments is "upvotes - downvotes". I don't think it's possible to separate the comment karma from the post karma, except for your own account.

How even for your own account would a user get their average karma per comment if the true value of karma per submission is hidden? Meaning my assumption is the public HN submission karma is the sum of the upvotes alone, not “upvotes minus downvotes” which I believe is the true karma users receive from a submission.

I can see my karma gain/loss for every single comment I make.

Thanks, I see now and agree; per user, per comment, each user is able to see the the sum of current “upvotes minus downvotes”; to get the average karma per comment for themselves, simply sum the karma of all their prior comments, then divide by the count of prior comments.

Am I missing something?

Ok now I've looked, if one was able to see individual karma for each user who submitting a reply to the submission, the answer is sometimes but on more controversial topics the answer would be no as per

< Downvoting Comments

All comments start with a score of 1 point (but in order to prevent bandwagoning, the comment score is not visible to users other than the author). After users reach 501 Karma, they gain the ability to downvote another comment. Downvoted comments (i.e. with a score < 1) reduce their placement on the comment thread and will appear desaturated to other users deemphasize them. There is no upper limit on the score of a comment, but the minimum score is -4 points. Additional downvotes after that still subtract points from the user's Karma, but the comment won't go below -4. You cannot downvote comments which are direct replies to your own comment, and you cannot downvote 24 hours after the original comment was made.

/>

I even managed to work out something curious for myself - Even though the comment's recorded or listed karma can't dip below -4, but as I found in particular a user's karma can still take a significant hit if they've responded and annoyed a certain clique of people draw to the topic subject.

Agree, the karma below -4 counting, but not being shown would be an issue to calculate the average karma per user — but turns out that it appears submissions only add karma to users total karma, so assuming that it is true submission upvote karma is worth 0.5 regardless of context, then to get the average karma per submission simply sum the karma of all submissions, multiple by 0.5, then divide by count of submissions including the flagged and/or killed submissions; to see those, go to your profile, select show dead. To get the average karma per comment, just take the sum of the submission karma above, multiply it by 0.5, then take that amount and divide it by the count of comments by user including the flagged comments.

If I have missed something, let me know.

That's about it from what I see, but I'm just a newbie, however I don't think there's any additional prizes after reaching more than 500 or 1000 ... I could check the FAQ but I'm about to get off the web for the night.

Different topics evoke different engagement from members be it either positive, negative or both.

Question is unrelated a user’s total HN karma — it’s about formula to get average karma per comment, per the title.

Now you've clarified you mean for submissions, my reply wasn't relevant.

“Submissions” is the official term, per HN’s guidelines:

https://news.ycombinator.com/newsguidelines.html

FYI there used to be karma easter eggs above 500 total karma, but not sure if they exist anymore.