Transaction Services Training

DIO (Days Inventory Outstanding)

The average number of days a company holds inventory before selling it — a measure of inventory efficiency and supply chain management.

Also known as: Days Inventory Outstanding, Inventory days, Stock days

One-line definition

DIO tells you how long goods sit on the shelf before being sold — high DIO ties up cash in inventory.

Formula

DIO = (Inventory ÷ Cost of goods sold) × 365

TS angle

Rising DIO may indicate slow-moving or obsolete stock. TS teams assess inventory write-down risk and whether inventory provisions are adequate — excess inventory improperly valued inflates NWC and therefore equity value.

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