I have a problem with calculating CPC in Tableau. I have the cost and the number of the click but Tableau is not calculating the right CPC. the formula I used : [Cost]/[Click] I attached two tables in this request. first shows the table which I calculated all KPIs in Zeppelin. the second the calculation in Tableau.

The whole data set has many null and 0 values, but it is the same data set used in zeppelin.

May I ask for help,how to solve this issue?

The result of CPC is not correct in Tableau.

the issue is that Tableau is using aggregate functions when you add measures, and in this case of CPC calculation, it's not correct.

Tableau is doing [cost]/[click] division (on row-level) and then simply averages all those numbers (you are basically calculating an average of an already average number).

What you are after is a bit different and you have to fix the math to make sure all costs are aggregated first and then divided by sum of all clicks, so:

SUM([cost]) / SUM([clicks])

This will give you the correct and mathematically sound numbers.

Hope this helps.