About Inventory Turnover Calculator

Calculate inventory turnover rates and optimize stock levels. Part of the DevTools Surf developer suite. Browse more tools in the Business & Corporate collection.

Use Cases

• Calculate days-on-hand and annual turnover ratio from cost of goods sold and average inventory data.
• Identify slow-moving inventory categories that should be discounted or liquidated.
• Benchmark your turnover ratio against industry averages to assess relative efficiency.
• Project the working capital freed up by improving turnover by 1-2 turns per year.

Tips

• Calculate turnover separately for each product category — averaging across categories masks slow-moving SKUs that inflate holding costs.
• A higher turnover ratio is not always better: ratios above 12 (monthly turns) may signal understocking and lost sales from stockouts.
• Compare your ratio against industry benchmarks — grocery retail averages 20-30 turns per year; furniture averages 3-5.

Fun Facts

• Inventory turnover as a business metric dates to the early 20th century manufacturing era. Henry Ford ran Model T production with an inventory turnover of over 40, unprecedented for the era.
• Amazon's inventory turnover ratio exceeded 10 in 2022 (approximately every 5 weeks), compared to the retail industry average of 4-6 — a major competitive advantage in working capital efficiency.
• Just-in-time (JIT) manufacturing, popularized by Toyota in the 1970s, optimizes inventory turnover to approach infinity — components arrive just before they're needed, minimizing holding costs.

FAQ

What's a good inventory turnover ratio?

Benchmarks vary by industry: groceries 20-30, apparel 4-6, automotive parts 10-15, furniture 3-5, electronics 8-12. The calculator includes industry benchmarks for comparison.

How do I calculate average inventory?

Average inventory = (beginning inventory + ending inventory) / 2. For more accuracy, average monthly inventory values over the period. The tool accepts either input method.

What's the difference between inventory turnover and days sales of inventory (DSI)?

They're inverses: DSI = 365 / turnover ratio. A turnover of 12 means DSI of ~30 days. DSI is more intuitive for operational planning; turnover is more commonly used for financial comparison.