Inventory days
Also: days of inventory, days inventory outstanding, days on hand
Inventory days is inventory divided by cost of goods sold for a period, multiplied by the number of days in that period. It estimates how many days of sales the stock on hand would cover at cost. The result depends on the period chosen and on one-off items in cost of sales, and it says nothing about the age or saleability of the stock.
Merchandising and distribution teams read it together with stock composition, because the same number of days can be fresh season stock or old stock waiting for clearance. A rise while sales fall usually means intake was not cut quickly enough.
Nike's inventories fell 3.3% to $7,846m against revenue down 4.3%, and days of inventory rose to 112.5 from 110.2.