Inventory Aging Calculator (Days Inventory Outstanding / DIO)

Enter the current inventory value from your business records. Include goods, materials, or products you own and expect to use or sell. This tool estimates Days Inventory Outstanding (DIO), not how long a specific item has been on a shelf.

If current inventory is valued at $40,000, enter $40,000.

Direct costs usually means the costs tied directly to producing, buying, or delivering what you sell, such as materials, inventory purchases, product costs, freight, packaging, subcontractors, or job labor. For inventory-heavy businesses, use the costs most closely tied to the inventory or products sold.

If materials, inventory purchases, product costs, freight, and similar costs totaled $480,000 over the last 12 months, enter $480,000.