Inventory Turnover Ratio

Also known as stock turn · inventory turns · turnover ratio · stockturn · days of inventory · how many times stock turns

T=COGSIˉT = \frac{\mathit{COGS}}{\bar{I}}

Enter your known values, leave one input blank, and solves for the missing one. Try different units for next level excitement!

Learning zone

Divide the year's cost of goods sold by the average value of stock on hand and you get how many times the stockroom emptied and refilled. Two point four million dollars of cost against three hundred thousand dollars of stock is eight turns. Flip it and it reads more usefully: 365/8 is about 46 days of inventory sitting there.

The mistake that ruins the comparison is using revenue instead of cost of goods sold on top. Revenue includes your margin, inventory is valued at cost, and the ratio comes out inflated by exactly your markup. A shop running 40% margin that reports turns on revenue is claiming about 1.67 times the truth, and the number stops being comparable to anyone else's.

Turnover is also where inventory policy shows up in the financial statements. Ordering in EOQ lots sets average inventory near half the lot size, so halving the order quantity roughly doubles the turns. That looks like an unambiguous win on the balance sheet, and it is not, because it also doubles the number of orders you pay to place. Turnover measures one side of a trade-off, never both.

Inventory Turnover Ratio
T=COGSIˉT = \frac{\mathit{COGS}}{\bar{I}}
Where
  • TT= Turnover ratio (turns/yr)
  • COGS\mathit{COGS}= Cost of goods sold per year ($)
  • Iˉ\bar{I}= Average inventory value ($)
Missing one of these? Work it out first, then come back