What Is Inventory Turnover?

Inventory turnover measures how many times a business sells through its average inventory in a year. A turnover of 6× means your typical stock level converts into sales six times annually — equivalently, product sits about 61 days before selling. It's the core efficiency metric for any business that holds stock, because inventory is cash in physical form: every dollar on the shelf is a dollar not paying rent, funding marketing, or extending your runway.

How Inventory Turnover Is Calculated

Use cost of goods sold, not revenue, in the numerator — inventory is valued at cost, so dividing sales revenue by cost-valued inventory inflates the ratio by your markup and makes results incomparable. Some analysts do quote a sales-based version; it's fine for trend-watching within one company but useless for benchmarking. This calculator uses the standard COGS method, consistent with how Investopedia defines inventory turnover.

What Is a Good Inventory Turnover Ratio?

Entirely industry-dependent — the spread across sectors is enormous:

• Grocery & supermarkets: 12–20× (perishables force fast cycles)
• General retail & e-commerce: 4–8× is a common healthy band
• Apparel & fashion: 4–6×, with seasonal spikes and markdown risk
• Consumer electronics: 6–10× — obsolescence punishes slow movers
• Furniture, jewellery, luxury: 1.5–4× is normal; high margins compensate for slow cycles
• Restaurants: 25×+ on food inventory

Within any industry, the pattern holds: too low means capital trapped in slow or dead stock plus storage and obsolescence costs; too high can mean chronic stockouts, lost sales, and expensive rush reordering. The optimum is the fastest turnover you can run without missing sales.

How to Use This Calculator

Pull annual COGS from your income statement and inventory values from your balance sheet (beginning = last year's closing figure). Enter both inventory values for a proper average — or just the beginning value if that's all you have. You'll get your turnover ratio, days inventory outstanding, months of stock on hand, and the capital currently tied up in inventory, plus a health read. Rerun it quarterly with trailing-twelve-month COGS to catch trend changes early — deteriorating turnover shows up here quarters before it shows up as a cash crunch.

Worked Example

An e-commerce store's annual COGS is $480,000. Inventory started the year at $90,000 and ended at $70,000, so average inventory is $80,000. Turnover is $480,000 ÷ $80,000 = 6×, and DIO is 365 ÷ 6 = 61 days. That sits comfortably in the healthy retail band: stock converts to cash every two months, with $80,000 of working capital doing the job. If the owner cut average inventory to $60,000 at the same sales rate (8× turnover), they'd free $20,000 of cash permanently — real money for a business watching its burn rate.

How to Improve Inventory Turnover

• Find your dead stock: rank SKUs by individual turnover — the blended average always hides a tail of items that haven't moved in months; discount or bundle them out
• Reorder on data, not habit: set reorder points from actual sales velocity and supplier lead times rather than gut feel
• Buy smaller, more often: bulk discounts frequently lose to the carrying cost of the extra months of stock they create
• Forecast seasonality explicitly: most overstock is bought for a peak that was predicted from optimism instead of last year's numbers
• Negotiate consignment or returns for risky new lines so slow movers become the supplier's problem, not your balance sheet's

Connected Numbers Worth Checking

Turnover interacts directly with your profit margin — the classic retail trade-off is margin × turnover, and a 30%-margin product turning 8× out-earns a 50%-margin product turning 3×. It also feeds your break-even point through carrying costs, and any cash it frees flows straight into the balance your runway calculator starts from.

Frequently Asked Questions