Inventory Turnover

Inventory turnover measures how efficiently a company manages its inventory by calculating how many times it sells through and replaces its entire inventory during a period. The formula is: Inventory Turnover = Cost of Goods Sold / Average Inventory. A higher ratio indicates faster inventory movement, meaning the company is efficiently converting inventory to sales. The inverse (365 / Inventory Turnover) gives Days Inventory Outstanding (DIO) — how many days inventory sits before being sold.

Inventory turnover varies dramatically by industry. Grocery stores and fast-food chains might turn inventory 30-50 times per year (holding only 1-2 weeks of stock). Fashion retailers typically turn inventory 4-6 times. Automobile dealers and heavy equipment manufacturers might turn inventory only 2-4 times. Comparing turnover across different industries is meaningless — always benchmark against direct competitors.

For fundamental analysis, inventory turnover trends are highly informative. Declining turnover (inventory building up) can signal weakening demand, poor merchandising decisions, or obsolescence risk. This is particularly critical for technology companies (where products become obsolete quickly) and fashion retailers (where unsold seasonal inventory must be heavily discounted). Conversely, very high turnover might mean the company is understocked and losing sales opportunities. The most efficient operators find the optimal balance — enough inventory to meet customer demand without excess. Walmart's legendary supply chain management, Dell's build-to-order model, and Toyota's just-in-time manufacturing all represent different approaches to optimizing inventory turnover. Inventory buildup relative to sales growth is one of the most reliable early warning signals of business deterioration.