A ratio showing how many times a company's inventory is sold and replaced over a period. The days in the period can then be divided by the inventory turnover formula to calculate the days it takes to sell the inventory on hand or "inventory turnover days."

Although the first calculation is more frequently used, COGS (cost of goods sold) may be substituted because sales are recorded at market value, while inventories are usually recorded at cost. Also, average inventory may be used instead of the ending inventory level to minimize seasonal factors.

This ratio should be compared against industry averages. A low turnover implies poor sales and, therefore, excess inventory. A high ratio implies either strong sales or ineffective buying.

High inventory levels are unhealthy because they represent an investment with a rate of return of zero. It also opens the company up to trouble should prices begin to fall.

Things to Remember
A low turnover is usually a bad sign because products tend to deteriorate as they sit in a warehouse.
Companies selling perishable items have very high turnover.
For more accurate inventory turnover figures, the average inventory figure, ((beginning inventory + ending inventory)/2), is used when computing inventory turnover. Average inventory accounts for any seasonality effects on the ratio.

A low turnover rate may point to overstocking,[2] obsolescence, or deficiencies in the product line or marketing effort. However, in some instances a low rate may be appropriate, such as where higher inventory levels occur in anticipation of rapidly rising prices or expected market shortages.
Conversely a high turnover rate may indicate inadequate inventory levels, which may lead to a loss in business as the inventory is too low. This often can result in stock shortages.
Some compilers of industry data (e.g., Dun & Bradstreet) use sales as the numerator instead of cost of sales. Cost of sales yields a more realistic turnover ratio, but it is often necessary to use sales for purposes of comparative analysis. Cost of sales is considered to be more realistic because of the difference in which sales and the cost of sales are recorded. Sales are generally recorded at market value, i.e. the value at which the marketplace paid for the good or service provided by the firm. In the event that the firm had an exceptional year and the market paid a premium for the firm's goods and services then the numerator may be an inaccurate measure. However, cost of sales is recorded by the firm at what the firm actually paid for the materials available for sale. Additionally, firms