New Inventory Turnover by Items report flaws

Good afternoon The Big Cahoona in CT,

Welcome to the QuickBooks Community! I will be happy to share some details here. Inventory turnover refers to the amount of time that passes from the day an item is purchased by a company until it is sold. One complete turnover of inventory means the company sold the stock that it purchased, less any items lost to damage or shrinkage. 

However, I do see you have a large number of days.  A high number of turnover days for a new product suggests there might be an issue with how the product's cost of goods sold or inventory levels are being tracked in QuickBooks. Therefore, there are a few troubleshooting steps you can take to assist: 

1. Verify Initial Inventory:
   Check the initial quantity of the new product entered in QuickBooks and ensure it's accurate.
2. Review Sales Transactions:
   Make sure all sales of the new product have been properly recorded in QuickBooks.
3. Double-Check Calculations:
   Verify the accuracy of the COGS and average inventory calculations for the new product.
4. Consult with an Expert:
   If you're unsure about how to troubleshoot, consider contacting a QuickBooks expert or accountant for assistance.

Please let me know if the issue is resolved. I will be here, looking forward to your response. See you later. 

@The Big Cahoona in CT 

Inventory turnover ratio is your COGS divided by the average inventory for the period (report period, which appears to be a little over 8 years based on your screenshot).  Inventory turnover days is 365 divided by the inventory turnover ratio:

Turnover ratio = COGS / average inventory for the period

Turnover days = 365 / turnover ratio

If your COGS is negative, that will cause both the turnover ratio and turnover days to be negative.  Is that what you're seeing?