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Inventory Turnover Calculator.

Measure how often inventory is sold during a consistent reporting period.

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Average inventory: $25,000.00

Average inventory

$25,000.00
Inventory turnover: 4 x

Inventory turnover

4.00x
Days inventory: 91.3 days

Days inventory

91.3days

Turnover uses COGS ÷ ((opening inventory + closing inventory) ÷ 2). Keep all values in the same currency and period.

FAQs

How is inventory turnover calculated?

Inventory turnover is COGS divided by average inventory, where average inventory is the opening and closing balance average.

What period should I use?

Use COGS and inventory balances from the same reporting period and label the period length consistently.

Cite this calculator

Canonical URL: https://mathify.one/fr/business/inventory-turnover

Cite as: Mathify. (2026). Calculatrice: Inventory Turnover. https://mathify.one/fr/business/inventory-turnover

Use Cases

Assess inventory efficiency

Business owners and managers use the turnover ratio to evaluate how efficiently inventory is managed. A higher ratio indicates faster selling and less money tied up in stock.

Example: A retailer with COGS of $500,000 and average inventory of $100,000 has a turnover of 5, meaning inventory sells five times a year.

Plan purchasing and cash flow

Knowing days inventory helps in planning reorder schedules and managing cash flow. It shows how long current stock will last, aiding in budget and procurement decisions.

Example: If days inventory is 60, you know you have about two months of stock on hand, so you can time your next purchase accordingly.

Frequently Asked Questions

How is the inventory turnover ratio calculated?
The inventory turnover ratio is calculated by dividing the cost of goods sold (COGS) by the average inventory. Average inventory is the sum of opening and closing inventory divided by two. For example, if COGS is $100,000 and average inventory is $25,000, the turnover ratio is 4.
What does days inventory mean?
Days inventory (or days sales of inventory) indicates how many days on average it takes to sell the entire inventory. It is calculated by dividing the number of days in the period by the inventory turnover ratio. For instance, if the period is 365 days and turnover is 5, days inventory is 73 days.
Why is the period length optional?
The period length is optional because the inventory turnover ratio itself does not require it. However, if you want to calculate days inventory, you need to specify the number of days in the reporting period (e.g., 365 for a year, 90 for a quarter). Without it, only the turnover ratio is provided.

Tips & Common Mistakes

Tips

  • Use accurate COGS and inventory values from your financial statements for the most reliable results.
  • Ensure opening and closing inventory are for the same period to get a correct average.
  • Compare your turnover ratio with industry benchmarks to gauge performance.
  • If you calculate days inventory, use the actual number of days in your reporting period (e.g., 365 for a year, 90 for a quarter).

Common Mistakes to Avoid

  • Using sales revenue instead of cost of goods sold (COGS) – this inflates the turnover ratio.
  • Forgetting to average the inventory – using only closing inventory can skew the result.
  • Mixing different period lengths when comparing turnover ratios – always use the same period for consistency.

Last updated: August 13, 2026