Turns is an inventory velocity metric defined as:
Annualized cost of sales amount divided by average inventory investment (for category and subcategory metrics).
Annualized net quantity sold divided by average quantity on hand (for product/location-specific metrics)
The higher the turns, the quicker you are moving product in and out of your inventory. Specific values that are considered good vary from industry to industry.
Non-stocked items and drop ship sales are excluded from these calculations.