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Days Inventory Outstanding Calculator.

Calculate inventory days from average inventory, COGS, and reporting-period days.

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Days inventory outstanding: 60.83

Days inventory outstanding

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FAQs

How is Days Inventory Outstanding calculated?

COGS and inventory must use the same reporting period.

Use Cases

Inventory Management Efficiency

Track how efficiently your company turns inventory into sales. A high DIO may indicate overstocking or slow-moving products, while a low DIO suggests strong sales and lean inventory.

Example: A retailer with average inventory of $500,000 and annual COGS of $2,000,000 has a DIO of 91.25 days.

Cash Flow Planning

Understand how long cash is tied up in inventory. This helps in forecasting working capital needs and negotiating supplier terms.

Example: If DIO increases from 30 to 45 days, you may need additional cash to fund inventory.

Frequently Asked Questions

What is Days Inventory Outstanding (DIO)?
DIO measures how many days on average a company holds inventory before selling it. It is calculated as (Average Inventory / Cost of Goods Sold) × Number of Days in the period. A lower DIO indicates faster inventory turnover.
How do I calculate DIO with this calculator?
Enter your average inventory value, total cost of goods sold (COGS) for the period, and the number of days in that period (e.g., 365 for a year). The calculator divides average inventory by COGS, then multiplies by the days to give your DIO.
What is a good DIO number?
A 'good' DIO varies by industry. Retail and grocery typically have lower DIO (e.g., 20-40 days), while manufacturing or luxury goods may have higher DIO (e.g., 60-100+ days). Compare your DIO to industry benchmarks and your own historical trends.

Tips & Common Mistakes

Tips

  • Use average inventory (beginning + ending inventory divided by 2) for a more accurate DIO, especially if inventory fluctuates seasonally.
  • Ensure COGS matches the same period as your inventory average. For annual calculations, use annual COGS and 365 days.
  • Compare your DIO over multiple periods to spot trends. A rising DIO may signal slowing sales or excess inventory.
  • Benchmark your DIO against industry peers to see if your inventory management is competitive.

Common Mistakes to Avoid

  • Using ending inventory instead of average inventory, which can skew results if inventory levels vary significantly.
  • Mismatching periods: using annual COGS with a quarterly inventory average, or vice versa, leads to incorrect DIO.
  • Forgetting to include all inventory costs in COGS, such as freight or storage, which can understate the true cost of goods sold.

Last updated: August 13, 2026