Definition
DIO estimates how many days inventory sits before it is sold. It is a component of the cash conversion cycle for inventory-heavy businesses.
Formula
DIO ~ average inventory / (COGS per day)
Example
If average inventory is $900k and COGS per day is $10k, DIO is 90 days.
How to use it
- Lower DIO usually improves cash conversion, but too low can risk stockouts.
- For SaaS, DIO is often near zero; focus on AR/AP instead.
- Track DIO alongside DSO and DPO to see the full cash cycle.
Common mistakes
- Reducing DIO too aggressively and causing stockouts.
- Comparing DIO without accounting for seasonality.
Measured as
DIO ~ average inventory / (COGS per day)
Misused when
- Reducing DIO too aggressively and causing stockouts.
- Comparing DIO without accounting for seasonality.
Operator takeaway
- Lower DIO usually improves cash conversion, but too low can risk stockouts.
- For SaaS, DIO is often near zero; focus on AR/AP instead.
- Track DIO alongside DSO and DPO to see the full cash cycle.
- Tie Days Inventory Outstanding (DIO) to the same balance-sheet date, scenario, and decision memo you are using elsewhere in the model.
- Document which claims, costs, or adjustments your team includes before comparing numbers across forecasts, covenants, or valuation work.
Next decision
- Read Cash conversion cycle: turn working capital into runway if the decision depends on interpretation, policy, or trade-offs beyond the raw formula.
- Decide whether Days Inventory Outstanding (DIO) belongs in cash planning, valuation, or debt monitoring so the number is used in the right model.
Where to use this on MetricKit
Guides
- Cash conversion cycle: turn working capital into runway: A practical guide to the cash conversion cycle (CCC): how AR/AP timing changes cash, how to reduce days outstanding, and why runway depends on working capital.