Inventory turnover calculator
Inventory turnover is the number of times you sell through and replace inventory over a period. It is calculated as cost of goods sold ÷ average inventory, with both valued at cost.
Enter COGS and either your average inventory or your beginning and ending inventory to see your turns.
- Definition — Inventory turnover
- Inventory turnover measures how quickly stock converts into sales over a period — a year, season, or month. Higher turns mean inventory moves faster relative to how much you hold, but very high turnover can signal under-buying and lost sales, while very low turnover ties up cash and raises markdown risk. It pairs naturally with GMROI to test whether fast turns are also profitable.
- Inventory turnover = COGS ÷ average inventory (average inventory = (beginning + ending) ÷ 2)
- Used by: Merchandise planners, buyers, finance and operations teams
- Related: GMROI, weeks of supply, sell-through, gross margin
Merchandise planners, buyers, and finance teams assessing how efficiently inventory converts to sales across D2C and wholesale.
Use it in season reviews, when comparing categories or channels, and when deciding whether stock levels are too lean or too heavy.
Spreadsheets are useful when the process is small and controlled. They become risky when multiple teams need the same version of the plan, when assumptions change frequently, or when decisions must flow into POs, production, and allocation.
Enter average inventory directly, or leave it blank and the calculator uses (beginning + ending) ÷ 2.
- Compare the result to your own history and similar categories, not a universal benchmark.
- Pair turnover with GMROI to see whether fast turns are actually profitable.
- Check weeks of supply to translate turns into how long current stock will last.
- Make sure COGS and inventory are valued the same way (both at cost).
Pair turns with profitability using the GMROI calculator, translate stock into time with the weeks of supply calculator, or see typical ranges on the benchmarks page.
Frequently asked questions
- What is inventory turnover?
- Inventory turnover is the number of times a business sells through and replaces its inventory over a period. It is a measure of how quickly stock converts into sales — higher turnover means inventory is moving faster relative to how much you hold.
- How do you calculate inventory turnover?
- Inventory turnover = cost of goods sold ÷ average inventory, with both valued at cost. Average inventory is usually (beginning inventory + ending inventory) ÷ 2. For example, $400,000 COGS against $100,000 average inventory is 4.0 turns.
- What is a good inventory turnover for apparel?
- There is no single right number — healthy turnover depends heavily on category, price point, and channel. Basics and fast fashion tend to turn faster than premium or seasonal apparel. The most useful comparison is against your own history and similar categories rather than a universal benchmark.
- Is higher inventory turnover always better?
- Not necessarily. Very high turnover can signal under-buying and lost sales from stockouts, while very low turnover ties up cash and raises markdown risk. The goal is turnover that balances availability with capital efficiency for your category.
Your calculator result is one number. RetailNorthstar keeps the whole plan connected — line plan, OTB, assortment, buy, POs, and production.
- Inventory turnover is how many times average inventory is sold and replaced in a period.
- Inventory turnover = COGS ÷ average inventory, with both valued at cost.
- There is no universal target — healthy turns depend on category, price point, and channel.
- Pair turnover with GMROI for profitability and with weeks of supply to see how long stock will last.
- RetailNorthstar connects sales, inventory, receipts, and assortment so inventory productivity stays current across the workflow.