Quick answer
Inventory turnover = cost of goods sold ÷ average inventory. COGS of $600,000 with beginning inventory of $90,000 and ending inventory of $110,000 (average $100,000) gives 6 turns a year, or 60.8 days to sell inventory.
Enter COGS, beginning inventory and ending inventory. The calculator returns turnover and days to sell inventory.
Related tools: Inventory Reorder Point Calculator: Stock level at which to reorder. Economic Order Quantity Calculator: Order size that minimizes ordering and holding costs. Employee Turnover Calculator: Turnover rate from separations and average number of employees.
How to use the Inventory Turnover Calculator
- Enter cost of goods sold ($) (above 0).
- Enter beginning inventory ($) (0 or more).
- Enter ending inventory ($) (0 or more).
- Press Calculate to see the result, and use Reset to start again.
| Input | What to enter | Allowed values |
|---|---|---|
| Cost of goods sold | A number, in $ | > 0 |
| Beginning inventory | A number, in $ | ≥ 0 |
| Ending inventory | A number, in $ | ≥ 0 |
Formula and method
Formula
turnover = COGS ÷ average inventory
IEEE-754 double precision; shown to the decimals indicated.
Average inventory is the mean of opening and closing values.
Worked examples
This example is verified: each one is an automated test case that the live calculator must reproduce exactly.
Example 1
Inputs: Cost of goods sold = 600000; Beginning inventory = 90000; Ending inventory = 110000.
| Result | Value |
|---|---|
| Inventory turnover | 6 |
| Days to sell inventory | 60.8 |
The first line is the headline result (inventory turnover). Below it the inventory Turnover Calculator lists days to sell inventory, which describe the same case from other angles. IEEE-754 double precision; shown to the decimals indicated.
Days to sell
365 ÷ 6 = 60.8 days. A higher turnover means stock sells faster, tying up less cash and risking less obsolescence. Too high a figure can signal stock-outs.
Comparing
Typical turnover varies enormously: grocers turn inventory many times a year, while jewellers turn it once or twice. Compare with your industry and your own history, and use the same period for COGS and inventory.
How the result changes with cost of goods sold
Holding every other input at the first worked example, this table changes only cost of goods sold. It shows how sensitive the answer is to that one value; each row was produced by running this calculator.
| Cost of goods sold | Inventory turnover | Days to sell inventory |
|---|---|---|
| 300000 | 3 | 121.7 |
| 600000 | 6 | 60.8 |
| 1200000 | 12 | 30.4 |
| 2400000 | 24 | 15.2 |
What happens with invalid input
These messages are produced by the calculator itself, so you know what to fix.
- Cost of goods sold: entering "0" shows "Cost of goods sold must be greater than 0." beside that field and no result.
- Beginning inventory: entering "0" shows "Average inventory must be positive." beside that field and no result.
Choosing between the Inventory Turnover Calculator and similar calculators
Each row shows what a related calculator on this site asks for and what it returns, so you can pick the one that matches your question.
| Calculator | You enter | It returns |
|---|---|---|
| [Inventory Reorder Point Calculator](/business/inventory-reorder-point-calculator/) | average daily demand, lead time and safety stock | Reorder point |
| [Economic Order Quantity Calculator](/business/economic-order-quantity-calculator/) | annual demand, cost per order and holding cost per unit per year | Economic order quantity |
| [Employee Turnover Calculator](/business/employee-turnover-calculator/) | separations and average number of employees | Turnover rate |
| [Margin Calculator](/business/margin-calculator/) | cost and revenue | Gross margin |
| [ROI Calculator](/business/roi-calculator/) | amount invested and final value | ROI |
Background: business metrics
Business ratios depend on exactly which costs and revenues you include, so read each page's definition. Two common checks: break-even units = fixed costs ÷ (price − variable cost per unit), so $50,000 of fixed costs with a $10 price and $5 variable cost breaks even at 10,000 units; and net profit margin = net profit ÷ revenue, so $20,000 profit on $100,000 revenue is 20%.
Return on investment ignores time: 20% over five years is far less impressive than 20% in one, so compare returns over the same period.
Assumptions and limitations
- Average inventory must be positive
If a required value is empty, not a number, or outside its allowed range, the form marks that field with a message and shows no result instead of a misleading number. The automated checks deliberately try invalid entries for cost of goods sold and beginning inventory to confirm this.
Frequently asked questions
What is average inventory?
The mean of beginning and ending inventory.
Is higher turnover always better?
Not if it causes lost sales from shortages.
How does it feed into DIO?
DIO is 365 divided by turnover.
What does the Inventory Turnover Calculator calculate?
How many times inventory is sold and replaced. It returns Inventory turnover and Days to sell inventory.
What formula does the Inventory Turnover Calculator use?
turnover = COGS ÷ average inventory. Average inventory is the mean of opening and closing values.
What do I need to enter in the inventory Turnover Calculator?
You enter Cost of goods sold ($), Beginning inventory ($) and Ending inventory ($).
How is the result rounded or limited?
IEEE-754 double precision; shown to the decimals indicated. Average inventory must be positive.
What is an example of a inventory Turnover result?
With cost of goods sold 600000, beginning inventory 90000 and ending inventory 110000, the inventory turnover is 6.
Where does the method come from?
The method follows: OpenStax, Principles of Accounting, Volume 1: Financial Accounting (Rice University): inventory turnover and days in inventory.
Related calculators
- Inventory Reorder Point Calculator — Stock level at which to reorder.
- Economic Order Quantity Calculator — Order size that minimizes ordering and holding costs.
- Employee Turnover Calculator — Turnover rate from separations and average number of employees.
- Margin Calculator — Profit, gross margin and markup from cost and revenue.
- ROI Calculator — Return on investment, with optional annualized return.
- Markup Calculator — Selling price from cost and markup percentage.
Sources
- OpenStax, Principles of Accounting, Volume 1: Financial Accounting (Rice University): inventory turnover and days in inventory
Content last reviewed 2026-11-04. Formulas and worked examples are checked by automated tests against independently computed values.