Inventory Turnover Calculator

Inventory turnover counts how many times a business sells and replaces its stock in a period. It is the clearest single measure of how hard the money tied up in goods is working.

turnover = cost of goods sold ÷ average inventory

days to sell = 365 ÷ turnover

Use cost, not revenue

This is the error worth avoiding first.

Inventory sits on the balance sheet at cost. Revenue includes the margin. Dividing revenue by inventory therefore compares two things measured on different bases and produces a number that is too high by exactly the markup.

A business with ₹60,00,000 of cost of goods sold, ₹90,00,000 of revenue and ₹10,00,000 of average inventory has a turnover of 6, not 9. The 9 is a 50% overstatement, and it is what a great many spreadsheets report.

Average inventory should be the average across the period — at minimum the opening and closing balances halved, and preferably a monthly average, because a single year-end figure is usually taken at the seasonal low.

What the numbers mean

With ₹60,00,000 of cost of goods sold:

Days to sell is usually the more intuitive figure. A turnover of 6 says stock sits for two months; a turnover of 12 says one.

The right level depends entirely on the trade:

Jewellery at 1.5 is normal and a grocer at 1.5 is in serious trouble. Comparison is only meaningful within a sector.

The cash tied up in stock

This is why turnover matters more than the ratio itself suggests.

Every rupee of inventory is a rupee of cash converted into goods. It earns nothing while it sits, and it cannot pay wages or rent.

The business above with ₹10,00,000 of average inventory that improves turnover from 6 to 8 needs only ₹7,50,000 to support the same sales. ₹2,50,000 of cash is released, permanently, without selling anything more or raising the price.

For a business borrowing at 12%, that is ₹30,000 a year of interest saved as well. For one not borrowing, it is ₹2,50,000 available for something productive.

The cost of the alternative is equally concrete. Holding cost — storage, insurance, financing, obsolescence, shrinkage — typically runs 20% to 30% of inventory value a year in Indian retail. Two months of excess stock is not free; it costs a few percent of its own value.

Margin times turnover

A single percentage never ranks retail categories correctly, because it ignores how often the money recycles.

GMROI — gross margin return on inventory — is the figure that does:

GMROI = gross margin % × turnover

The staples line looks least attractive on margin alone and beats jewellery fourfold on the measure that matters. This is why supermarkets run 2% net margins profitably and why "increase your margins" is not advice that applies everywhere.

Ranked by GMROI, shelf space and purchasing budget go to different products than a margin ranking would suggest — and that reallocation is usually the highest-return decision available to a small retailer.

When a high turnover is a bad sign

The ratio has no opinion about why it is high.

Stockouts. Selling out constantly produces excellent turnover and lost sales that appear nowhere in any figure. A business optimising turnover alone will eventually optimise itself into empty shelves.

Under-buying. Insufficient working capital forces small orders, which raises turnover and also raises per-unit purchase cost, because volume discounts are missed.

Deep discounting. Clearing stock cheaply moves it quickly and destroys margin. Turnover rises while GMROI falls, which is why the two should be read together.

The companion measures are the stockout rate and the fill rate — the share of demand actually met. Turnover with a low fill rate is efficiency measured only on the goods that happened to be there.

Where slow stock hides

Aggregate turnover conceals its own composition. A business with a healthy overall figure frequently has a long tail of items that have not moved in a year, offset by fast lines.

ABC analysis sorts inventory by value: roughly 20% of items typically account for 80% of value. Those deserve tight control and frequent counting; the rest can be managed loosely.

Ageing analysis groups stock by how long it has been held — under 30 days, 30 to 90, 90 to 180, over 180. Anything past 180 days in a fast-moving category is unlikely ever to sell at full price, and holding it is a decision to keep paying storage on a loss already incurred.

The uncomfortable rule is that dead stock should be cleared at whatever it fetches. The purchase money is gone regardless; the only remaining question is whether to keep spending on storage and to keep the shelf space occupied.

Improving it

Order more often in smaller quantities. Halves the average holding for the same sales, at the cost of more freight and less volume discount. Worth modelling both ways.

Cut the slow tail. Fewer variants, deeper stock in what sells.

Improve forecasting. Most excess inventory is a forecasting error that was funded rather than corrected.

Negotiate consignment or sale-or-return with suppliers where possible, which moves the holding cost onto them.

Clear ageing stock deliberately, on a schedule, rather than when the shelf is needed.

The cash conversion cycle

Turnover measures one leg of a longer loop. The full picture is how many days pass between paying a supplier and being paid by a customer.

cash conversion cycle = days inventory + days receivable − days payable

A business holding stock for 61 days, collecting from customers in 45 and paying suppliers in 30 has a cycle of 76 days. For 76 days of every sale, the business funds the gap out of its own pocket, and the faster it grows the more funding it needs.

Each term is a lever. Shortening inventory days is what this calculator measures. Collecting faster — deposits, shorter credit terms, following up early — is usually the quickest win. Paying later is available but has a cost in supplier goodwill and in lost early-payment discounts.

A negative cycle is the strongest position in retail: the customer has paid before the supplier is due. Supermarkets and large online retailers run this way, which is why they can grow without external funding.

Counting the stock

None of these ratios means anything if the inventory figure is wrong, and it frequently is.

Physical counts against book records are the only way to detect shrinkage — theft, damage, misplacement and recording errors. In Indian retail, shrinkage of 1% to 3% of sales is common and is invisible until counted.

Cycle counting — counting a small subset continuously rather than everything once a year — catches errors faster and does not require closing the shop. Count the high-value 20% of items most often.

Valuation method matters. FIFO, weighted average and specific identification give different inventory values from identical stock when prices are moving, and therefore different turnover ratios. Indian accounting standards permit FIFO and weighted average but not LIFO. Whichever is used, use it consistently — a change of method makes the ratio incomparable with the prior year.

What this calculator assumes

• Cost of goods sold, not revenue, is the numerator.
• Average inventory across the period; opening and closing halved is the minimum acceptable approximation.
• A 365-day year for the days-to-sell figure; use 360 if your accounts do.
• One aggregate figure. A per-category calculation is considerably more useful and requires per-category cost data.
• The ratio measures speed, not profitability. Read it alongside gross margin, and preferably as GMROI.