Inventory Turnover Calculator (DSI

Supply Chain Management & Inventory Velocity Metrics

Inventory turnover is a critical liquidity ratio that measures how efficiently a company manages its inventory stock assets.

Core Supply Chain Formulas

• Average Inventory Value: Average Inventory = ÷ 2

• Inventory Turnover Ratio: Turnover = Cost of Goods Sold (COGS) ÷ Average Inventory

• Days Sales in Inventory (DSI): DSI (days) = (Average Inventory ÷ COGS) × 365 = 365 ÷ Turnover Ratio

Industry Turnover Benchmarks

• Fast-Moving Consumer Goods (FMCG) & Grocery: 12.0+ turns/year (DSI ≤ 30 days)

• Apparel & Retail Merchandise: 6.0 to 10.0 turns/year (DSI 36 to 60 days)

• Automotive & Heavy Industrial Machinery: 2.0 to 4.0 turns/year (DSI 90 to 180 days)

Strategic Business Impact & Carrying Costs

Maintaining an optimal inventory turnover balance prevents supply chain bottlenecks. Excessive inventory inflates warehouse storage, insurance, and interest holding costs, while dangerously low inventory leads to costly stockouts.

How to Use This Calculator

Enter your Annual Cost of Goods Sold (COGS) (e.g. 500000 in ), Beginning Period Inventory Balance (e.g. 80000 in ), and Ending Period Inventory Balance (e.g. 120000 in ). Results update instantly as you type — adjust any value to compare scenarios.

The Formula

Formula Reference: Inventory Turnover Calculator (DSI)

Input variables:

cogsUsd — Annual Cost of Goods Sold (COGS)

beginningInventoryUsd — Beginning Period Inventory Balance

endingInventoryUsd — Ending Period Inventory Balance

Computed outputs:

inventoryTurnoverRatio — Inventory Turnover Ratio

daysSalesInInventoryDsi — Days Sales in Inventory (DSI)

averageInventoryUsd — Average Inventory Value

turnoverSpeedRating — Supply Chain Velocity Rating

Mathematical relationships extracted from calculation logic:

avgInv = (begInv + endInv) / 2

dsi = safeDiv(avgInv, cogs) * 365

Standard: GAAP accounting standards and SEC financial reporting conventions

Worked Example

A retail store with 500,000 annual COGS, 80,000 beginning inventory, and 120,000 ending inventory: Average inventory is 100,000, resulting in 5.00 annual inventory turns and a 73.0-day holding period (DSI).

Understanding Your Result

Optimal inventory management balances holding costs (typically 20–30% of inventory value annually: storage, insurance, obsolescence, capital cost) against ordering costs. EOQ minimizes the total of these two cost types. Safety stock protects against demand variability and lead time variability — the standard formula uses service level z-scores: 95% service level z=1.645, 99% z=2.

• Days inventory outstanding (DIO) benchmark: retail 30–60 days, manufacturing 50–80 days, distribution 20–40 days. Below industry average DIO is generally better.