Cfrgtkky

I have an Excel 2016 Pivot Table question. I want to use the % of Grand Total value that a pivot table can generate, as an input for a calculated field.
Reason - I'm attempting to calculate a true monthly target based on 2 factors:

1. What was the target for the day (can change every week)


2. What percent of volume was received for the day (The weight of the day on the whole month)

Generally (without a pivot table), I get my volume by day and total it for the month. Then for each day it is volume of day / volume of month for a percentage. Then, I can use SumProduct(% of day, target) & it will produce a goal for the month based on the daily goal and the impact it had on the month.
IE for 3 days:

vol target Weight

48 55% 39.0%

50 60% 40.7%

25 75% 20.3%

SumProduct(Target, Weight) will produce 61.1% target for the month.

Now, using a pivot table, I can do an average of the target. This works when I'm using a daily or weekly view, but begins to fail whenever I look at a monthly view. I can use the pivot table to generate the weight by doing a sum of Volume and displaying as % of grand total. But how to do I create a calculate field or measure where I can get the % of grand total as an input to correctly view a target for the month? In my mind the formula inside the pivot should look something like =SUMPRODUCT(% of Grand Total [Volume], Target)