I am not clear with your requirement. This table is your requirement or your data? It is better to attach a sample file, so that we can understand your problem & requirement more clearly.
Unfortunately my trial has expired, but it was one thing that I needed to see if Tableau could accomplish as it is a requirement for the client. Let me try to explain one more time. I have two pieces of data: # of users that login daily to a website and total users registered (running total). I am trying to figure out utilization. The catch is that the client's monthly calculation always uses the total registered users data from the last day of the month. So you would need to use: (Sum of daily logins)/(Total registered users on the last day of the month).
Let me know if that helps. If I get the trial extended I will post a sample.
I think you wants to calculate per day utilization. This is simple. Drag your measure field & right click on it & go to Quick Table Calculation. Choose Percentage of Total.
When you edit this field it gives you this formula.
SUM([Sales]) / TOTAL(SUM([Sales]))
Now the problem you will faced that you want it to compute according to month. For that you have option of compute using this in Tableau:-
Hope this May Help!