π Inventory Turnover Calculator
How fast stock becomes sales.
Inventory turnover ratio
Estimates for planning only, not financial advice.
Inventory turnover divides cost of goods sold by average inventory to show how many times stock sells through in a year. With COGS of $1.2M and average inventory of $0.3M, turnover is 4.00x, meaning inventory cycles every 91.3 days. Faster turns mean less cash trapped on shelves.
How to Use This Calculator
Enter COGS from the income statement and average inventory (beginning plus ending over two) from the balance sheet. The calculator returns turns per year and days of inventory on hand.
Enter cost of goods sold for the period.
Enter average inventory for the same period.
Read turns and days on hand. For the margin side of inventory productivity, try our GMROI calculator.
The Formula
COGS is used instead of sales because inventory is carried at cost; using sales would inflate turns by the markup. Average inventory smooths seasonal spikes, though businesses with wild seasonality should average quarterly points instead of just endpoints. Days on hand translates the ratio into plain language: 4x turnover is 91 days of stock, 12x is about 30 days. Compare against industry norms, because a grocer's 12x and a jeweler's 1x can both be excellent.
Worked Example
COGS of $1.2M divided by average inventory of $0.3M gives turnover of 4.00x per year. Days on hand: 365 / 4 = 91.3 days. If this retailer tightens buying and cuts average inventory to $0.24M with the same COGS, turnover rises to 5x and days fall to 73, freeing $60,000 of cash. If instead sales slump and COGS drops to $0.9M on the same inventory, turnover falls to 3x and days stretch to 122, the classic warning sign of overstocking into weak demand.
High vs Low Turnover
High turnover usually signals strong sales and lean operations, but it can also mean stockouts and lost sales if shelves go bare. Low turnover ties up cash, raises obsolescence and storage costs, and often precedes markdowns. The sweet spot is industry-specific and strategy-specific: fast fashion lives on speed, luxury lives on scarcity. Trend matters more than level; turnover falling for three straight quarters is the number that should trigger a buying review.
My advice: track turns monthly by category and investigate every sustained decline. Rising days on hand is often the first financial symptom of a demand problem, arriving quarters before it hits the income statement. Pair this with margin analysis, because fast turns on zero margin are just busy work.
Estimates for planning only, not financial advice.
Frequently Asked Questions
What is inventory turnover?
COGS divided by average inventory: how many times a company sells through its stock in a period. Higher generally means leaner, faster-moving inventory. It is a core efficiency ratio in retail, wholesale, and manufacturing.
What is a good inventory turnover ratio?
It depends entirely on the industry. Grocers run 10x to 15x, apparel 3x to 5x, jewelers near 1x. Compare against direct competitors and your own history, never against a universal benchmark.
Why use COGS instead of sales?
Inventory sits on the books at cost, so the numerator should be at cost too. Using sales inflates turnover by the gross margin and makes high-margin firms look artificially efficient.
What are days of inventory on hand?
365 divided by turnover: how many days of sales the current stock covers. It is the same information as turnover in more intuitive units, and the input to working-capital forecasts.
Is high turnover always good?
No. Excessively high turnover can mean chronic stockouts, rushed reorders at premium freight, and lost sales. The optimum balances carrying cost against stockout cost, and it differs by product.
What causes turnover to fall?
Overbuying, slowing demand, obsolete stock, or all three. Falling turnover with flat sales is the classic early signal of inventory bloat. Investigate by SKU before it becomes a markdown event.
How does turnover affect cash flow?
Directly. Every extra day of inventory is a day of cash trapped on shelves. Cutting days on hand from 91 to 73 on $1.2M of COGS frees roughly $60,000, which is why operators obsess over this ratio.
Should I use FIFO or average inventory?
Use average inventory (beginning plus ending over two) at minimum to avoid endpoint distortion. For seasonal businesses, average four quarterly balances. The costing method matters less than consistency.
How do e-commerce sellers use turnover?
The same way, with faster clocks. Online sellers watch turns weekly because storage fees and return rates punish slow stock harder. A 6x turner with 30% returns can be less profitable than a 4x turner with 5% returns.
What is dead stock?
Inventory with no sales for an extended period, typically 6 to 12 months depending on the category. It scores zero on turnover while occupying the denominator, so clearing it, even at a loss, usually lifts the ratio.