Inventory Turnover Calculator
How efficiently does your business sell through inventory? Calculate your turnover ratio, see how many days items sit before selling, or benchmark against your industry. Works with any currency.
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How to Use This Calculator
Tab "Turnover Ratio"
Enter your annual Cost of Goods Sold (COGS), beginning inventory, and ending inventory. The calculator computes your average inventory and inventory turnover ratio. A higher ratio means you cycle through stock faster.
Tab "Days to Sell"
Uses the same inputs to calculate Days Sales of Inventory (DSI) — the average number of days an item sits in inventory before being sold. Lower DSI means faster-moving stock and less cash tied up in warehousing.
Tab "Industry Benchmark"
Enter your turnover ratio and select your industry. The calculator shows whether you are above, within, or below the typical range for your sector, and displays a reference table of benchmarks across seven industries.
The Formulas
Average Inventory = (Beginning Inventory + Ending Inventory) / 2
Inventory turnover ratio:
Turnover = Cost of Goods Sold / Average Inventory
Days Sales of Inventory (DSI):
DSI = 365 / Turnover Ratio
All calculations are universal. No country-specific tax or accounting rules are applied. Results are estimates — actual performance depends on product mix, seasonality, and supply-chain factors.
Worked Examples
Example 1 — Healthy retail: COGS $1.2M, average inventory $150K
A retailer has annual COGS of $1,200,000 with beginning inventory of $140,000 and ending inventory of $160,000.
Turnover of 8.0× means this retailer sells through its entire inventory 8 times per year, with the average item sitting 45.6 days before selling. That is healthy for general or electronics retail.
Example 2 — Inventory piles up: COGS $1.2M, average inventory $250K
Same COGS, but inventory grows — beginning inventory $200,000, ending inventory $300,000. Perhaps a seasonal overstock or slowing demand.
Turnover drops from 8.0× to 4.8× and DSI jumps from 46 to 76 days. That extra $100K in average inventory is cash tied up in unsold stock — increasing storage costs and obsolescence risk.
Example 3 — Benchmarking electronics: your 8× vs a competitor at 12×
You run an electronics store with a turnover ratio of 8×. The industry benchmark for electronics is 6–10×, so you are within range. But a competitor achieves 12×.
Your 8× is on par with the industry average. The competitor at 12× moves stock in ~30 days versus your ~46 days — meaning they free up cash faster, reduce holding costs, and can reinvest sooner. Studying their supply chain, pricing strategy, or product mix could reveal efficiency gains.
Understanding Inventory Turnover
Why inventory turnover matters
Inventory is one of the largest uses of cash in any product-based business. The faster you convert inventory into sales, the less cash is locked up in warehouses and the lower your holding costs (storage, insurance, spoilage, obsolescence). Inventory turnover quantifies this speed.
High vs low turnover
High turnover generally signals strong sales and efficient purchasing — you buy what sells and do not overstock. Low turnover suggests excess inventory, weak demand, or poor purchasing decisions. However, extremely high turnover can indicate frequent stockouts that lose sales.
What moves the needle
To improve turnover: reduce slow-moving SKUs, negotiate smaller and more frequent deliveries, use demand forecasting, run clearance on aging stock, and review your reorder points regularly. Benchmark against your own historical performance and industry peers.
DSI as a complement
While turnover tells you how many times you cycle through inventory, DSI translates that into calendar days. For operational planning — lead times, reorder cycles, cash flow forecasting — DSI is often the more intuitive metric.
Frequently Asked Questions
What data do I need for this calculator?
You need three numbers from your financial statements: annual Cost of Goods Sold (COGS) from the income statement, and beginning and ending inventory from the balance sheet. These are standard line items in any set of financial reports.
Should I use COGS or revenue for turnover?
Use COGS. Revenue includes your profit margin, which would inflate the turnover ratio and make comparisons between businesses with different markups unreliable. COGS represents the actual cost of the goods that moved through inventory.
How often should I check inventory turnover?
Most businesses review turnover quarterly or monthly. Seasonal businesses should also compare the same quarter year over year to account for natural demand fluctuations. Tracking the trend over time is more valuable than any single snapshot.
Can I use this for service businesses?
Inventory turnover is designed for businesses that hold physical inventory — retail, wholesale, manufacturing, and e-commerce. Pure service businesses typically do not carry inventory and would use different efficiency metrics like revenue per employee or utilisation rate.
Why do grocery stores have much higher turnover than furniture stores?
Groceries are perishable, low-cost, and purchased frequently — so they cycle through inventory rapidly (14–20× per year). Furniture is expensive, durable, and bought infrequently — leading to slower turnover (3–5×). Neither number is "better"; each is appropriate for its industry.