Average Inventory - Inventory Turns

We have a snap shot of our inventory at the end of each month. I need to calculate inventory turns and need to figure out how to get average inventory. I can do this in custom mode, but I may want to change my periods from rolling 12, ytd, etc and can’t make the custom dynamic.

How about just setting your offset to pull in the 12 months rolling but in the formula divide by 12?

There is a function {Period_Count} though so you could do the following:

Thank you! I was dividing by 12 but didn’t realize I needed the squiggly brackets.