Inventory Days on Hand Calculator

About this calculator

Inventory Days on Hand (also called Days Sales of Inventory, or DSI) measures how many days your current stock will last at the rate it is currently being sold or used: units in stock divided by average daily usage. It is one of the core inventory-management metrics alongside inventory turnover, and a low number of days signals a risk of stockouts while a high number ties up cash in slow-moving inventory.

Retailers, manufacturers, and wholesalers track this figure to decide when to reorder and how much safety stock to carry, since it directly feeds into reorder-point planning. Comparing days-on-hand across product lines also highlights which SKUs are overstocked and which are at risk of running out before the next shipment arrives.