Spirit Airlines Inc Days in Inventory is 60.62 for the quarter ending March 31, 2024, a 32.12% change year over year. The days in inventory ratio measures the average number of days it takes for a company to sell its inventory. It is calculated by dividing 365 by the ratio of cost of revenue to the average of inventory and other current assets. This ratio indicates the efficiency of inventory management and the company's ability to convert inventory into sales within a specific period. A lower number of days in inventory is generally preferable.