Inventory

Inventory is the stock of goods a business holds for the purpose of production, sale, or use in operations. On a company's balance sheet, inventory is a current asset because it is expected to be converted to cash within one operating cycle or one year. For manufacturers, retailers, and distributors, inventory is often the largest single asset on the balance sheet.

Think of inventory like a warehouse full of cash that has not been spent yet: it has value, but only if it moves.

The Three Categories of Inventory

Not all inventory is the same. The category depends on where the goods sit in the production or sales process. Understanding these distinctions matters for how you value inventory on your financial statements.

• Raw materials: Inputs purchased but not yet used in production. Steel coils at an auto parts manufacturer. Cotton at a clothing producer. These are carried at purchase cost until they enter the production process.
• Work-in-progress: Items that have entered production but are not yet complete. This category is also called WIP. Valuing WIP requires capturing the cost of the raw materials used, the labor applied so far, and the overhead allocated to that production stage.
• Finished goods: Completed products ready for sale. These carry the fully loaded production cost and represent the inventory closest to generating revenue.

Inventory Valuation Methods and Why They Matter

The method you use to assign cost to your inventory has a direct impact on your gross profit, your taxes, and your balance sheet. Three methods are widely used under U.S. Generally Accepted Accounting Principles.

First-In, First-Out (FIFO) assumes the oldest inventory is sold first. During periods of rising input costs, FIFO produces higher ending inventory values on the balance sheet and higher gross profits on the income statement, because the cost of goods sold reflects the older, cheaper purchases.

Last-In, First-Out (LIFO) assumes the most recently acquired inventory is sold first. During inflation, LIFO produces lower ending inventory values and lower taxable income, which is why U.S. companies use it as a tax strategy. LIFO is prohibited under International Financial Reporting Standards, so companies reporting under IFRS cannot use it.

Weighted average cost calculates a blended cost per unit based on total inventory cost divided by total units. It smooths price fluctuations and sits between FIFO and LIFO in terms of its impact on gross margin and taxes.

Key Inventory Ratios That Measure Performance

Inventory performance shows up directly in your financial ratios. These are the three you need to monitor most closely.

Inventory turnover ratio measures how many times a company sells and replaces its inventory in a period. You calculate it by dividing cost of goods sold by average inventory. A higher ratio signals faster-moving goods and more efficient operations. A declining ratio points to slowing sales or growing stockpiles.

Days inventory outstanding converts the turnover ratio into a number of days. Divide 365 by the inventory turnover ratio. If your days inventory outstanding is 45, it takes you 45 days on average to convert your inventory to a sale. Walmart consistently reports days inventory outstanding below 45 days. For a specialty retailer, a figure above 90 days could indicate obsolescence or demand problems.

Gross margin return on investment measures the gross profit generated per dollar of inventory investment. It combines margin efficiency with inventory turnover into a single profitability metric used heavily in retail and distribution analysis.

Inventory and Working Capital Management

Inventory is one of the three key components of working capital alongside accounts receivable and accounts payable. Too much inventory ties up cash unnecessarily and increases storage, insurance, and obsolescence risk. Too little inventory results in stockouts, missed sales, and damaged customer relationships.

Companies that manage inventory tightly generate stronger free cash flow. Amazon's logistics infrastructure and just-in-time replenishment systems allow it to carry inventory for far shorter periods than traditional retailers, freeing billions of dollars in working capital that would otherwise sit in warehouses.

Inventory Write-Downs and Their Impact

When inventory loses value below its carrying cost, accounting standards require a write-down to the lower of cost or net realizable value. Net realizable value is the estimated selling price minus costs to complete and sell the goods.

A write-down is a direct hit to your gross profit. It increases cost of goods sold in the period the write-down is recorded and reduces the inventory balance on your balance sheet. Companies in fast-moving industries, like consumer electronics or fashion, record write-downs regularly because unsold inventory quickly becomes obsolete. Apple's supply chain management is specifically designed to minimize inventory aging and reduce the need for write-downs on components and finished products.

Just-in-Time Inventory vs. Safety Stock Approaches

Just-in-time inventory management aims to receive goods exactly when they are needed in production or for sale, eliminating the cost of holding excess stock. Toyota pioneered this approach and reduced warehousing costs and waste across its manufacturing operations. The strategy works well when supply chains are reliable and demand is predictable.

Safety stock is the opposite approach: holding a buffer of inventory above your expected needs to guard against supply disruptions or demand spikes. The COVID-19 pandemic exposed the vulnerability of companies that had eliminated safety stock in favor of just-in-time efficiency. By 2021 and 2022, many manufacturers shifted strategy to carry more safety stock of critical components, particularly semiconductors, accepting higher inventory costs in exchange for supply chain resilience.

Sources:
https://www.fasb.org/standards/accounting-standards-updates
https://www.ifrs.org/issued-standards/list-of-standards/ias-2-inventories/
https://www.sec.gov/edgar