Inventory Turnover Calculator
Calculate your inventory turnover ratio and days sales of inventory, key metrics for inventory management efficiency.
Inventory turnover is one of those ratios that reveals a lot about operational health with a single number. A high turnover means you're selling through stock quickly, lean, efficient, low carrying cost. A low turnover means cash is sitting in inventory instead of working. For a retail or product business, this is one of the first numbers I look at.
Inventory turnover ratio = COGS ÷ Average Inventory. Days Sales of Inventory = 365 ÷ Turnover Ratio. DSI tells you how many days it takes to sell through your average inventory level.
How inventory turnover is calculated
Inventory turnover ratio = Cost of Goods Sold ÷ Average Inventory. Average inventory is (beginning inventory + ending inventory) ÷ 2. Using average inventory rather than ending inventory produces a more accurate picture by smoothing seasonal fluctuations. Some analysts use revenue instead of COGS in the numerator, both are valid, but COGS-based turnover is more commonly used for comparisons and tends to be more accurate for operational purposes.
Days Sales of Inventory (DSI)
DSI = 365 ÷ Inventory Turnover Ratio. DSI tells you the average number of days it takes to sell through your entire inventory. A DSI of 45 means your inventory turns completely every 45 days. DSI is often more intuitive than the ratio for operational planning, it directly answers "how long will this inventory last?"
Industry benchmarks
Turnover benchmarks vary dramatically by industry. Grocery and food service: 15–25x (high perishability drives rapid turnover). Apparel retail: 4–6x. Auto dealerships: 6–12x. Electronics: 8–12x. Furniture: 4–6x. Industrial manufacturers: 3–6x. Always compare to industry-specific benchmarks rather than a universal standard.
Low turnover warning signs
Low turnover relative to industry norms may indicate: overbuying (purchasing more than demand requires), slow-moving or obsolete inventory, poor demand forecasting, pricing issues (items priced too high), or economic slowdown affecting demand. Carrying excess inventory ties up working capital, increases storage costs, and risks obsolescence and markdown losses.
High turnover considerations
Very high turnover can indicate lean, efficient operations, or it can signal stockouts and lost sales. If you're frequently running out of fast-moving products, high turnover may be costing you revenue. The goal is the right turnover rate for your industry and business model, not necessarily the highest possible.
Frequently asked questions
What's the difference between FIFO and LIFO for this calculation?
FIFO (first in, first out) assumes oldest inventory is sold first; LIFO (last in, first out) assumes newest is sold first. The choice affects COGS and ending inventory values, which changes the turnover ratio. LIFO is only permitted under US GAAP; IFRS requires FIFO or weighted average. Consistent methodology matters more than which you choose for internal comparisons over time.
How does turnover relate to cash flow?
Higher turnover generally improves cash flow by converting inventory to cash faster. The cash conversion cycle, days inventory outstanding plus days sales outstanding minus days payables outstanding, measures how quickly a business converts its investments in inventory and receivables into cash. Reducing DSI is one lever for improving the cash conversion cycle.
Should I track turnover by SKU?
Yes, for meaningful operational insights. An overall turnover of 8x might hide fast-moving products at 25x and dead stock at 1x. SKU-level turnover identifies which products to reorder aggressively, which to discount and clear, and which to discontinue.