Two divisions show your stock risk. Sales velocity is units sold divided by days, so 84 units over 28 days is 3 a day. Days of inventory is units on hand divided by velocity, so 60 units at 3 a day is 20 days (Practical Ecommerce, 2026). Compare 7, 28 and 90-day windows, and judge the result against your reorder lead time. … Read More