Inventory Turnover & DSI Calculator
Calculate your Inventory Turnover Ratio (ITR), Days Sales of Inventory (DSI), and inventory holding drag to free up trapped working capital.
Inventory Turnover Formulas & Days Sales of Inventory (DSI) Guide
The Inventory Turnover Ratio (ITR) measures how many times a business sells and replaces its inventory over a given period. Higher turnover indicates strong sales demand and lean working capital efficiency.
• $600,000 COGS ÷ $100,000 inventory
• $600k ÷ $100k
• Turnover = 6.0 Turns / Year
• 365 days ÷ 6.0 turns
• 365 ÷ 6.0
• DSI = 60.8 Days on Hand
• $100,000 inventory balance @ 25% cost
• Storage, obsolescence, insurance
• $25,000 Annual Carrying Cost
Financial InputsManagerial accounting
Ready to paste into operations reviews or working capital scorecards.
Inventory Turnover Benchmarks by Industry Vertical
| Industry Sector | Typical Turnover (ITR) | Average Days to Sell (DSI) | Working Capital Implications |
|---|---|---|---|
| Grocery & Supermarkets | 14x – 20x | 18 – 26 Days | Extremely high velocity; perishable goods prevent holding. |
| Fast Fashion & Apparel | 4.5x – 7.0x | 52 – 81 Days | Seasonal drops require prompt clearance to avoid markdowns. |
| Consumer Electronics | 6.0x – 9.0x | 40 – 60 Days | High obsolescence risk; requires disciplined JIT supply chain. |
| Automotive Dealerships | 2.5x – 4.0x | 90 – 145 Days | High unit values incur floor-plan financing holding interest. |
| Luxury Goods & Jewelry | 1.5x – 2.5x | 145 – 240 Days | Substantial trapped capital compensated by high gross margins (60%+). |
Understanding Inventory Velocity: The Mathematical Framework
Inventory turnover measures how effectively a company manages its stock, balances purchasing against customer demand, and minimizes trapped liquidity.
The Two Core Formulas
The Hidden Costs of Slow-Moving Stock
Holding excess inventory carries substantial hidden drag beyond simple warehouse rent:
1. Opportunity Cost of Capital
Every dollar sitting as unsold stock is cash that cannot be deployed into customer acquisition, product development, or yield-generating treasuries.
2. Shrinkage & Obsolescence
Goods held for extended periods suffer damage, expiry, packaging degradation, and seasonal demand obsolescence requiring write-downs.
Frequently Asked Questions About Inventory Turnover
How is the inventory turnover ratio calculated?↓
Inventory turnover ratio is calculated by dividing Cost of Goods Sold (COGS) by Average Inventory for a given period: Inventory Turnover = COGS / Average Inventory. If beginning and ending inventory are known, Average Inventory = (Beginning Inventory + Ending Inventory) / 2.
What is Days Sales of Inventory (DSI)?↓
Days Sales of Inventory (DSI), also known as days to sell or inventory period, measures the average number of days a business takes to turn its inventory into sales: DSI = (365 / Inventory Turnover Ratio) or (Average Inventory / COGS) * 365.
What is considered a good inventory turnover ratio?↓
For most retail and e-commerce companies, a healthy inventory turnover ratio falls between 4 and 8 turns per year (meaning inventory is cleared every 45 to 90 days). Grocery stores with perishable goods often turn inventory 14 to 20 times per year, while luxury retailers or high-end manufacturers may operate at 2 to 4 turns.
Why must COGS be used instead of total sales revenue?↓
Inventory on the balance sheet is valued at cost (not retail sales price). Using sales revenue in the numerator inflates the ratio artificially due to the retail markup, creating an inaccurate mismatch between cost-basis inventory and retail-basis revenue.
What are the holding costs of unsold inventory?↓
Holding costs (or carrying costs) typically total 20% to 30% of total inventory value per year. These costs include warehousing space, commercial insurance, shrinkage/theft, obsolescence, damage, and capital financing interest.
Authored by Arham Bilal
Calculations aligned with GAAP managerial cost accounting standards and supply chain inventory turnover benchmarks.
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