What is the inventory turnover ratio?

Inventory turnover ratio = COGS ÷ Average Inventory. It tells you how many times your entire inventory stock was sold and replaced during the period. A higher ratio means you are selling through inventory faster.

What is Days Sales of Inventory (DSI)?

DSI = (Average Inventory ÷ COGS) × Period Days. It represents the average number of days it takes to sell your current inventory. Lower DSI means faster movement; higher DSI may indicate excess stock.

What is a good inventory turnover ratio?

It depends on the industry. Grocery and fast-moving consumer goods often exceed 10×, apparel typically falls between 4–6×, and furniture or heavy equipment can be 1–3×. Compare your result to the benchmarks shown in the tool.

What is sell-through rate?

Sell-through rate = (Units Sold ÷ Beginning Inventory Units) × 100. It shows the percentage of available inventory that was actually sold in the period. Retailers aim for 80% or higher on seasonal merchandise.

How is average inventory calculated?

Average Inventory = (Beginning Inventory + Ending Inventory) ÷ 2. Using the average smooths out seasonal swings and gives a more accurate picture of your typical stock level during the period.

Does this tool store my data?

No data is sent to any server. All calculations run entirely in your browser and nothing is saved or transmitted.

Inventory Turnover Calculator

Enter your COGS and average inventory to instantly calculate your inventory turnover ratio, days sales of inventory (DSI), and sell-through rate with industry benchmarks.

Inventory Inputs

Period

Cost of Goods Sold (COGS) for the period

Beginning Inventory Value

Ending Inventory Value

Sell-Through Rate (optional)

Beginning Units

Units Sold

Industry Benchmark

Enter your COGS and inventory values, then click Calculate

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Summary

This inventory turnover calculator helps retailers, ecommerce sellers, and supply chain managers measure how efficiently they convert inventory into sales. Enter your cost of goods sold (COGS) and average inventory value to get the turnover ratio, days sales of inventory (DSI), and sell-through rate. Results are benchmarked against common industry ranges so you can instantly see whether your stock levels are healthy, lean, or overstocked.

How it works

Select your period (monthly, quarterly, or annual) to set the calculation context.
Enter your Cost of Goods Sold (COGS) — the total cost of products sold during the period.
Enter your beginning and ending inventory values; the calculator averages them automatically.
Optionally enter your beginning inventory units and units sold to compute the sell-through rate.
Click Calculate to see the turnover ratio, DSI, sell-through rate, and an industry benchmark comparison.

Use cases

Identify slow-moving SKUs that are tying up working capital.
Set reorder points and safety stock levels based on realistic DSI.
Compare inventory efficiency across product categories or warehouse locations.
Prepare financial reports or investor decks that include inventory health metrics.
Benchmark store performance against industry averages before a buying season.
Negotiate better payment terms with suppliers by demonstrating strong turnover.
Detect overstock situations early to plan markdowns or promotions.
Track improvement in inventory management quarter over quarter.

Frequently Asked Questions

Last updated: 2026-05-29 · Reviewed by Nham Vu