Days of inventory (DSI)
Days of inventory, or days sales of inventory, estimates how many days it takes to sell through current stock, calculated as (average inventory ÷ COGS) × 365, or 365 ÷ inventory turnover. Lower days-of-inventory means faster-moving inventory and less cash tied up; very high DSI signals overstock or dead-stock risk.
How it's calculated
Convert your stock level into the number of days it would take to sell at the current pace:
Days of inventory = (average inventory ÷ COGS) × 365 = 365 ÷ inventory turnover
A DSI of 60 means, at the current sales rate, you hold about two months of stock.
Why it matters
DSI translates an abstract turnover ratio into days, which maps directly onto cash and shelf life. Lower DSI means inventory moves fast and cash isn't trapped; a very high DSI flags overstock or dead stock building up. Shopify merchants use it to set reorder cadence and catch slow movers before they become write-offs.
Track this automatically
Logistified calculates and monitors metrics like this across your whole Shopify catalog and turns them into reorder alerts and purchase orders.