The inventory turnover ratio is one of the most revealing numbers in retail. It tells you how many times you sold and replaced your entire stock over a period — and, indirectly, how much cash you have tied up on shelves and in the back room. Sell through inventory quickly and you free up cash, cut storage and obsolescence, and keep products fresh. Turn it too slowly and capital sits idle in stock that may never sell at full price.
This guide covers exactly what the ratio is, the formula (and the mistake most people make with it), a full worked example, healthy benchmarks by industry, and eight practical ways to improve it.
What is the inventory turnover ratio?
Inventory turnover measures how many times a business sells through and replaces its average inventory during a set period, usually a year. A turnover of 6 means you sold the equivalent of your average stock six times — roughly once every two months.
It is a measure of efficiency. A higher ratio generally means strong sales and lean, well-managed stock. A lower ratio suggests overbuying, weak demand, or slow-moving lines that tie up cash and risk becoming dead stock.
The inventory turnover formula
The standard formula uses cost of goods sold (COGS), not sales revenue:
Average inventory smooths out seasonal swings between the start and end of the period:
Use COGS, not sales — the common mistake
Some people divide sales revenue by inventory. Because sales include your markup, this inflates the ratio and makes turnover look better than it really is. COGS is measured at cost — the same basis as your inventory value — so the two match. Always prefer COGS ÷ average inventory. If you can only get sales figures, remember the result will run higher than a true cost-based ratio.
A worked example
Suppose a shop has, over one year:
- Cost of goods sold: $600,000
- Inventory at the start of the year: $90,000
- Inventory at year end: $110,000
First, average inventory = ($90,000 + $110,000) ÷ 2 = $100,000.
Then inventory turnover = $600,000 ÷ $100,000 = 6.
This shop turns its stock six times a year. To translate that into days, see days sales of inventory below.
What is a good inventory turnover ratio? Benchmarks by industry
There is no single "good" number — it depends heavily on what you sell, your margins, and how perishable the goods are. Low-margin, fast-moving categories such as groceries need high turnover; high-margin, considered purchases such as jewelry or furniture run much lower, and that is perfectly healthy. Use the typical ranges below as a starting point, then compare against your own trend over time.
| Industry / category | Typical turnover (per year) |
|---|---|
| Grocery & supermarket | 12–20 |
| Restaurants & food service (perishables) | 20–40+ |
| Consumer electronics | 6–10 |
| General / variety retail | 6–12 |
| Automotive parts | 5–8 |
| Apparel & fashion | 4–6 |
| Furniture & home | 4–6 |
| Jewelry & watches | 1–3 |
These are general benchmarks, not hard rules. A boutique with premium margins may thrive at a turnover of 3, while a discount grocer may need 18 to make its thin margins work.
How to read your number
A low ratio
Turnover well below your industry norm usually points to overstocking, weak demand, poor buying, or too many slow lines. The cost is real: cash locked in stock, higher storage and insurance, markdowns, and obsolescence. See how to avoid overstocking and how to reduce dead stock.
A high ratio
High turnover is usually good — but it can be too high. If you are turning stock so fast that you run out, you are losing sales to stockouts and disappointing customers. The fix is not to buy more of everything, but to hold the right safety stock and set smart reorder points.
Days sales of inventory (DSI): turnover in days
Turnover as a count ("6 times") is useful, but many owners find days easier to act on. Days sales of inventory converts the ratio into the average number of days it takes to sell your stock:
In our example, DSI = 365 ÷ 6 ≈ 61 days. On average, an item sits about two months before it sells. Track DSI alongside turnover — falling DSI is a sign your buying and merchandising are getting sharper.
Eight ways to improve inventory turnover
- Clear dead and slow stock. Use markdowns, bundles, or promotions to convert aging inventory into cash you can reinvest in fast sellers.
- Buy to demand, not to gut feel. Let sales data drive purchasing. Identify your best-selling products and reorder those first.
- Set reorder points and safety stock. Replenish based on real sell-through and lead times so you avoid both stockouts and overbuying.
- Order smaller and more often. Where suppliers allow, more frequent, smaller orders keep less cash on the shelf without risking availability.
- Forecast seasonality. Plan buys around your real demand curve so you are not left with post-season stock — see managing seasonal demand.
- Price and promote slow movers. A modest, deliberate discount that moves stock beats a full-price item that never sells — just discount without losing profit.
- Apply ABC analysis. Give your top-selling "A" items the most space, attention, and stock; keep low-value "C" items lean.
- Shorten supplier lead times. Reliable, faster suppliers let you hold less stock for the same service level — see negotiating with suppliers.
Track inventory turnover automatically
Calculating turnover by hand once a year tells you little you can act on. The value comes from watching it per product, per category, and per branch, in real time. RushFlow tracks cost of goods sold and stock movements as you sell, so turnover, days sales of inventory, dead stock, and reorder points stay up to date across every location — turning a backward-looking accounting figure into a live buying and merchandising tool.