This has become a bit of a hot topic for me recently ..... it's an interesting question. We don't typically ask, how much time should a developer be a developer? Or a manager a manager?
The simple knee jerk answer would be to state, that as a role, this is what you do.... so all the time. But I don't believe that is right now that simple?
I found this great survey ... https://dzone.com/articles/scrum-master-duties-what-are-you-doing-all-day-sur - which helps as it means I don't need to make it up! It's worth a read .. but the conclusion from over 200 Scrum Masters was;
A typical Scrum team based on this survey has more than seven members and runs a two-week sprint. On average, the team's Scrum Master allocates his or her time roughly as follows, normalized to hours per week:
If you do the math — the total amount of time spent on Scrum ceremonies, educating herself, or training teammates and stakeholders, respectively, is about 11.50 hours/week.
So 11 1/2 hours ..... but then I looked at two parts
The times above are based on 'an average of what they do' and not on 'what they should do' - these numbers are low for how Scrum Guides define the timeboxed activities, and low for how I see the time too.... I'd suggest something more like
Are we done .. I don't think so ... isn't there more a Scrum Master can / should be doing?
Here's some
This is really hard to put a figure too - and some could be contained in "learning, training" above .... but we could conservatively put 2hrs 15 mins on this .... (make my numbers better)
So we have a revised total of AT LEAST 15 hours .....
Agree / Disagree? ..... it's 50% of a working week - when I look at how important the Scrum Master role is for the success of the team - it seems about right to me.