Creating a difference in percents metric

[pthatch1]

I would like to create a metric that can be broken down by a dimension that calculates the difference between two already calculated percents.

For example, let's say I want to see what % of purchases items in my store encompass, relative to the percent of visitors.  I create a table with "Visitors" and "Purchases" on the top and use a dimension to break down all the store items on the left. This shows me the # of purchases and visitors for each item and also conveniently breaks down percents for each column.

Now I can see that Item A accounts for 40% of purchases in my store but gets just 20% of visitors and is performing better than expected by 20%, while Item B accounts for 10% of purchases but gets 70% of visitors and is performing worse than expected by -60%. But I'd like to automatically be able to calculate that for all the possible values of the dimension.

My ideal metric is:

([purchases of x] / [total purchases]) - ([visitors to x] / [total visitors])

but right now I can't achieve that without manually inserting the the totals:

([purchases of x] / 12000) - ([visitors to x] / 140320)

Because I can't find a way to specify the difference between the overall total and the total for the dimension item using adobe's tools.

Any idea if this is possible?

[yuhuisg · Accepted solution]

This worked for me:

To get the Grand Total of a metric, click its gear icon, then choose "Grand total".