About the Inventory Turnover Calculator
This inventory turnover calculator measures how many times you sell through your average inventory in a period and how many days, on average, stock sits before it is sold. Enter cost of goods sold for the period along with beginning and ending inventory, and it returns the turnover ratio, days inventory outstanding (DIO) and average inventory.
Retailers, wholesalers, e-commerce sellers and manufacturers use turnover to spot slow-moving stock, plan purchasing and free up working capital. Set a target turnover rate and the calculator shows the average inventory you would need at that pace and how much cash would be released compared with today.
Turnover uses cost of goods sold rather than sales so that both sides of the ratio are measured at cost. Use a 365-day period for annual figures, or change the days to match a quarter or month.
With the default inputs, the inventory turnover ratio is 5 x. Change any value above to recalculate instantly.
How to use the inventory turnover calculator
- 1Enter cost of goods sold for the period from your income statement.
- 2Enter inventory at cost at the start and end of the same period.
- 3Set the number of days in the period (365 for a year).
- 4Optionally enter a target turnover to see the cash you could free up.
Formula and method
Inventory turnover divides the cost of goods sold during a period by the average value of inventory held, giving the number of times the stock was sold and replaced. Averaging the beginning and ending balances smooths out a single high or low count; if inventory swings a lot, average monthly balances instead.
Days inventory outstanding converts turnover into time: the number of days in the period divided by turnover. The target figures invert the formula — COGS ÷ target turns — to show the average inventory level that would support the same sales at a faster turnover, and the difference is working capital released.
- COGS
- Cost of goods sold during the period
- Average inventory
- Mean of beginning and ending inventory, at cost
- DIO
- Days inventory outstanding (days sales of inventory)
Worked examples
Wholesaler, annual figures
Average inventory is ($90,000 + $110,000) ÷ 2 = $100,000, so turnover is $500,000 ÷ $100,000 = 5 times a year, or 365 ÷ 5 = 73 days. At 8 turns, average inventory would be $62,500, freeing $37,500 of cash.
Retailer with slower stock
With $280,000 of average inventory, $1.2 million of COGS gives 4.29 turns and about 85 days on the shelf. Reaching 6 turns would need only $200,000 of inventory, releasing $80,000.
Quarterly check
For a 90-day quarter, $90,000 of COGS over $22,500 of average inventory is 4 turns, meaning stock sells in about 22.5 days. The business is already at its 4-turn target.
Frequently asked questions
What is a good inventory turnover ratio?+
It depends on the industry. Grocery and fast-moving consumer goods often turn stock 10 or more times a year, while furniture, jewelry and heavy equipment may turn only 2–4 times. Compare with businesses that sell similar products.
Should I use sales or COGS for inventory turnover?+
Use COGS. Inventory is recorded at cost, so dividing sales (which include your markup) by inventory at cost inflates the ratio. Some quick industry reports use sales, so check which basis a benchmark uses.
What does high inventory turnover mean?+
High turnover usually means strong sales and lean stock, which frees cash and reduces spoilage and obsolescence. If it is too high, however, you may be losing sales to stockouts or paying more in rush orders.
What is days inventory outstanding?+
DIO (also called days sales of inventory) is the average number of days it takes to sell your inventory. It equals days in the period divided by turnover and is one component of the cash conversion cycle.
How can I improve inventory turnover?+
Clear slow-moving SKUs with promotions, order smaller quantities more often, improve demand forecasting, negotiate shorter supplier lead times and drop products that rarely sell.
Results are estimates for educational purposes and are not financial advice. Rates, fees and terms vary — confirm with your lender or a licensed advisor before making decisions.