Business
Inventory Turnover Calculator
Average beginning and ending inventory, divide cost of goods sold by that average to calculate inventory turnover, and convert the turnover rate into days inventory outstanding for the entered analysis period. Review average monthly COGS alongside the ratios to keep both stock velocity and spending scale visible.
Average inventory-
Inventory turnover-
Days inventory outstanding-
Average monthly COGS-
Exact scenario comparison
Ending inventory scenarios
Exact scenario comparisonEnding inventory changes while all other entered assumptions remain constant.
| Ending inventory | Average inventory | Inventory turnover | Days inventory outstanding | Average monthly COGS |
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How to use Inventory Turnover Calculator
- Enter cost of goods sold and beginning and ending inventory on the same cost basis for the same analysis period.
- Review average inventory, turnover, days inventory outstanding, and monthly COGS without substituting sales revenue for COGS.
- Use monthly or daily inventory averages and product-level analysis when seasonality, growth, stockouts, or obsolete stock make two endpoint balances misleading.
Calculator guide
Understanding Inventory Turnover Calculator
Inventory turnover relates cost of goods sold to the average inventory investment carried during the same period. The calculator also converts turnover into days inventory outstanding, but the result is meaningful only when the cost basis, period length, and inventory balances are consistent.
Calculation method
How the calculation works
Average beginning and ending inventory, divide annual cost of goods sold by that average, and convert turnover into days held. Average beginning and ending inventory, divide annual cost of goods sold by that average, and convert turnover into days held.
Worked situations
Practical examples
- Beginning inventory of $210,000 and ending inventory of $270,000 produce a simple average inventory balance of $240,000.
- Annual COGS of $1.2 million divided by $240,000 of average inventory produces five modeled turns during the period.
- With a 365-day analysis period, five turns correspond to approximately 73 days inventory outstanding.
Better inputs
Useful tips
- Use cost-based inventory values because the numerator is cost of goods sold, not sales revenue.
- Use monthly or daily average inventory when seasonality or rapid growth makes a two-point average unrepresentative.
- Analyze product families separately when slow-moving items are hidden by fast-moving high-volume products.
Before relying on the result
Limitations and common mistakes
- Average inventory uses only the beginning and ending balances and can miss peaks, shortages, or seasonal builds.
- Write-downs, obsolescence, consignment, work in process, purchase commitments, stockouts, and product mix are not adjusted.
- Accounting policies and business models differ, so comparisons require consistent definitions and comparable periods.
Reference
Key terms
- Cost of goods sold
- Cost assigned to goods sold during the analysis period.
- Average inventory
- Beginning inventory plus ending inventory divided by two in this simplified model.
- Inventory turnover
- Cost of goods sold divided by average inventory.
- Days inventory outstanding
- Entered days in the period divided by calculated inventory turnover.
Important note
Calculated from the entered values using the displayed accounting method. Reconcile material decisions with source records and applicable accounting policy.
Frequently asked questions
Is higher inventory turnover always better?
No. Higher turnover can reflect efficiency, but it can also indicate insufficient safety stock, stockouts, lost sales, or unstable supply.
Why use COGS instead of revenue?
Inventory is normally carried on a cost basis, so using COGS keeps the numerator and denominator on a more consistent valuation basis.
Can beginning and ending inventory be enough for a seasonal business?
Often not. A monthly or daily average can better represent inventory carried throughout a highly seasonal period.
How should obsolete inventory be handled?
Use balances consistent with the applicable accounting policy and analyze obsolete or nonmoving stock separately because it can materially weaken practical turnover.