What This Tool Does
Enter cost of goods sold and average inventory to calculate the inventory turnover ratio and days of inventory on hand. The result section stays hidden until a valid calculation succeeds.
Formula, Inputs, and Period Settings
The calculator uses these formulas:
Inventory turnover = Cost of goods sold / Average inventoryDays of inventory on hand = Period days / Inventory turnover
- Enter COGS and average inventory for the same period and cost basis.
- Average inventory can be calculated as
(starting inventory + ending inventory) / 2before you enter it. - Choose Annual (365 days), Quarter (90 days), or Month (30 days) to set the period used for days on hand.
- The currency selector changes the displayed symbol only. It does not convert the values or apply an exchange rate.
How to Use the Inventory Turnover Calculator
- Enter cost of goods sold for the period.
- Enter average inventory for the same period.
- Choose a currency symbol, if needed. This changes the displayed symbol but not the values.
- Select Annual (365 days), Quarter (90 days), or Month (30 days).
- Select Calculate turnover. The result section then shows the turnover ratio, days on hand, formula, and assumptions table.
- Select Reset to clear the entered values, restore
$and Annual (365 days), hide the result, and clear errors.
Validation and Edge Cases
Cost of goods sold must be a number greater than or equal to zero. Average inventory must be a number greater than zero; zero is rejected because division by zero is undefined.
Zero COGS is accepted. It produces 0x turnover, while days of inventory on hand shows - in the headline result and n/a in the assumptions and text output.
Calculations use the entered numeric values. Displayed turnover is formatted to at most two decimals, and days of inventory on hand to one decimal.
Reading, Copying, and Downloading the Result
After a successful calculation, the result shows the inventory turnover ratio and days of inventory on hand. The assumptions table lists the entered values, period length, and calculated figures.
Select Copy result to copy the plain-text summary, or Download result (.txt) to download it as a .txt file. If clipboard access fails, the interface displays “Could not copy - select and copy manually.”
Limits and Privacy
The calculation runs locally from the values entered into the calculator. It does not fetch live inventory records, market prices, accounting data, rates, or other external data. It also does not model seasonality or product-line mix, choose or reconcile FIFO, LIFO, or weighted-average costing methods, or provide personalized accounting or financial advice.
Frequently Asked Questions
What is inventory turnover?
Inventory turnover is a ratio that measures how many times a business sells and replaces its inventory during a period. It is calculated by dividing cost of goods sold by average inventory for the same period, and is used to gauge how efficiently inventory is being managed.
What is the inventory turnover formula?
Inventory turnover = Cost of goods sold / Average inventory. Average inventory is typically the average of starting and ending inventory for the period. A higher ratio generally means inventory is sold and replaced more frequently.
How is days of inventory on hand calculated?
Days of inventory on hand = Number of days in the period / Inventory turnover ratio. Choose Annual (365 days), Quarter (90 days), or Month (30 days) to set the period length.
Why can't average inventory be zero?
Inventory turnover is calculated by dividing cost of goods sold by average inventory, so a value of zero for average inventory makes the ratio mathematically undefined (division by zero). The calculator requires average inventory to be greater than zero.
Does this tool fetch live inventory data or give personalized advice?
No. It performs a single, transparent calculation using only the numbers you type in - cost of goods sold and average inventory. It does not fetch inventory records, market prices, or accounting data, and it is not personalized financial or accounting advice.