How many times the stock sells through
Inventory turnover counts how often a business sells and replaces its stock in a year. It is the first number a lender or buyer looks at to judge whether the inventory on the balance sheet is an asset or a warehouse full of money that is not moving.
The formula
Cost of goods sold, not revenue — inventory is carried at cost, so the numerator must be too. Average inventory is the mean of opening and closing stock, which smooths out a seasonal peak at year end.
Worked example: $600,000 COGS against $120,000 of stock
- Turnover: 5.0 times a year
- Days of inventory: 365 ÷ 5 = 73 days
The stock on hand sells through roughly every ten weeks. That second figure, in days, is usually the more useful one, because it can be compared directly against supplier payment terms.
What the number looks like by trade
| Sector | Typical turnover | Days of stock |
|---|---|---|
| Grocery | 12–20× | 18–30 |
| Clothing retail | 4–6× | 60–90 |
| Furniture | 2–4× | 90–180 |
| Jewellery | 1–2× | 180–365 |
There is no universal target. A jeweller turning 1.5 times is normal; a grocer turning 1.5 times is about to go under. Compare against the same trade, not against a textbook figure.
Turnover against the cash cycle
73 days of stock financed on 30-day supplier terms means 43 days of inventory paid for out of the business's own cash before it sells. Multiply that gap by daily cost of sales — about $1,644 here — and roughly $70,700 is permanently tied up.
Raise turnover to 6 and the gap shrinks to 31 days, freeing about $20,000. This is why turnover improvements show up in the bank balance faster than almost any other operational change.
Too high is also a signal
Turnover far above the sector norm often means stock-outs rather than efficiency. Sales lost because the shelf was empty do not appear anywhere in this ratio, and a business optimising turnover alone will eventually find them in its revenue line.
What this calculator leaves out
Product mix. An overall turnover of 5 can hide one line turning 20 times and another turning once. Dead stock sits inside the average and drags it down, and only a line-by-line report exposes it.
Improving the figure without starving the shelf
The levers are ordering smaller quantities more often, dropping lines that turn slowly, and negotiating faster supplier delivery so safety stock can shrink. Each raises turnover without touching sales.
The wrong lever is simply ordering less. Turnover rises, stock-outs follow, and the lost sales cost more than the freed cash was worth. Measure fill rate alongside turnover or one will be optimised at the expense of the other.
Average, not year-end
Using closing stock alone distorts the ratio for any seasonal business. A retailer that clears the shelves before 31 December shows a flattering turnover on year-end stock and a realistic one on the average across the year.
Monthly averages are better still where they exist, because two data points can both be unusual.
Related calculators
- Days inventory outstanding — the same measure expressed in days
- Cash conversion cycle — inventory days combined with receivables and payables
- GMROI — what the stock earns, not just how fast it moves