Shopify Inventory Turnover and Dead Stock

Inventory turnover formula

Calculate both values for the same period and on the same cost basis. A common estimate of average inventory is (beginning inventory value + ending inventory value) ÷ 2. If inventory changes sharply during the period, monthly or weekly snapshots can give a more representative average than two endpoints.

Example: if annual cost of goods sold is $180,000 and average inventory at cost is $60,000, turnover is 3 times for the year. A rough days-on-hand equivalent is 365 ÷ 3, or about 122 days. This is an illustrative calculation, not a target for every store.

Interpret the ratio with context

A low ratio can point to excess buying, weaker demand, or a product whose sales are seasonal. A high ratio can indicate efficient movement, but it can also signal that stock is too lean and the store is missing sales. Compare like with like: use the same time window, valuation method, and product grouping.

• Review category and SKU differences instead of relying on one store-wide average.
• Compare seasonal items with the same season in prior periods where the data is available.
• Check whether sales were constrained by stockouts before treating low inventory as efficient.
• Pair turnover with gross margin, sell-through, lead time, and service-level goals.

There is no single “good” turnover rate for every Shopify merchant. Apparel, perishable goods, replacement parts, and durable products have different buying and selling cycles.

When slow-moving inventory becomes dead stock

Dead stock is inventory that has remained unsold long enough that normal demand is unlikely to sell it at the expected price. A slow mover is not automatically dead: a seasonal product may sell in a later period, and a low-volume replacement part may still be important to customers. Define review windows by category and product lifecycle rather than applying one arbitrary number of days to every SKU.

Common warning signs include no recent sales, rising days on hand, repeated markdowns, a discontinued product line, or seasonal goods left after their selling window. Confirm stock across locations and check returns, transfers, and open orders before deciding how much is truly available to clear.

A practical action plan for excess stock

1. Validate the record. Check on-hand quantities and recent movement so a data error is not mistaken for overstock.
2. Pause or revise reorders. Review open purchase orders and supplier lead times before placing another order.
3. Estimate recovery options. Compare a markdown, bundle, return-to-supplier option, resale channel, or donation with the cost of holding the item.
4. Set an owner and review date. Record the decision, expected result, and next check rather than leaving the SKU in an unreviewed report.
5. Change future buying inputs. Use the outcome to revise order quantities, reorder timing, or seasonal assumptions.

Inventory turnover is an analysis metric, not an instruction to discount everything with low movement. Protect margin and availability by making decisions at the SKU and category level.

Use Shopify inventory data to investigate

Start with a consistent period and compare cost of goods sold with average inventory value. Shopify's inventory reports documentation describes available inventory reporting. Report availability can depend on the store's plan and configuration, so verify the reports visible in your admin.

Supremo's published feature set includes inventory valuation, dead stock, ABC analysis, stock movement, and reorder analysis reports. The Supremo feature list describes the current scope. Use the ABC analysis guide to prioritize products by contribution, and review reorder points before changing replenishment.

Frequently asked questions

Sources

• Shopify, Inventory Turnover Ratio: Formula and How to Improve, published June 9, 2023.
• Shopify, What Is Dead Stock and How Can You Prevent It?, published April 3, 2026.