Inventories and Cost Measurement

Introduction and Context

Inventory is a current asset held for sale, in the process of production for sale, or consumed in producing goods or services. For a trading entity, inventory may consist of merchandise purchased for resale. For a manufacturer, it normally includes raw materials, work in progress, and finished goods. In service organizations, inventory may be limited, although supplies and work in progress can still be significant.

Inventory accounting matters because the amount assigned to ending inventory affects both the statement of financial position and profit. The basic relationship is:

Cost of goods available for sale consists of opening inventory plus purchases and other costs included in inventory. Assuming sales revenue is unchanged, overstating ending inventory understates cost of goods sold and overstates gross profit; understating ending inventory has the opposite effect. These effects may influence taxes, lending decisions, performance measures, executive remuneration, and investor judgments.

This chapter explains inventory measurement under the principles commonly associated with International Financial Reporting Standards, particularly IAS 2, while noting that local rules and tax regulations may differ. Students should always consult the applicable jurisdictional requirements.

Learning Objectives

By the end of this chapter, you should be able to:

1. Define inventory and identify costs included in its measurement.
2. Apply specific identification, FIFO, and weighted-average cost-flow methods.
3. Measure inventory at the lower of cost and net realisable value.
4. Use gross-profit and retail methods to estimate inventory when detailed records are unavailable.
5. Explain the effects of inventory decisions on profit, tax, controls, and business decisions.
6. Evaluate inventory systems, risks, ethical issues, and technology-enabled controls.

1. The Nature and Classification of Inventory

Inventory is recognized as an asset when the entity controls an economic resource, expects future economic benefits, and can measure the resource reliably. It becomes an expense, usually cost of goods sold, when the related goods are sold. Inventory classifications include:

Inventory does not include items that are held for another party under a genuine consignment arrangement. Goods held on consignment are normally included by the consignor until control passes to a customer, rather than by the consignee merely holding them.

2. Components of Inventory Cost

Inventory cost includes all costs of purchase, costs of conversion, and other costs incurred to bring inventory to its present location and condition.

2.1 Costs of purchase

Purchase cost includes the invoice price, import duties, non-recoverable taxes, transport, handling, and directly attributable acquisition costs. Trade discounts, rebates, and similar reductions are deducted. Recoverable value-added tax is generally excluded because it is recoverable from the tax authority.

2.2 Costs of conversion

For manufactured goods, conversion costs include direct labour and a systematic allocation of production overhead. Variable production overhead is allocated using actual use of production facilities, while fixed production overhead is allocated using normal capacity. Abnormal idle capacity is expensed rather than included in inventory.

A simplified conversion-cost relationship is:

This formula applies when the listed costs are properly attributable to production. Selling expenses, general administrative expenses that do not bring inventory to its present condition, abnormal waste, and most storage costs after production are excluded.

2.3 Other eligible costs

Other costs may be included where they are necessary to bring inventory to its present location and condition. Examples can include design costs for a specific customer order. Borrowing costs may be capitalized only in limited circumstances under applicable standards, such as qualifying inventories requiring a substantial period to become saleable.

Worked Example 1: Measuring initial cost

A company purchases goods for $50,000. It receives a 4% trade discount, pays non-recoverable import duty of $1,800 and freight of $1,200, and pays recoverable sales tax of $5,000. The inventory cost is:

• Net purchase price = $50,000 × (1 − 0.04) = $48,000
• Add import duty = $1,800
• Add freight = $1,200
• Exclude recoverable tax = $0 included
• Inventory cost = $51,000

The recoverable tax is not part of inventory because it represents a receivable from the tax authority. If the tax were non-recoverable, it would normally be included in cost.

3. Cost-Flow Assumptions

The physical movement of goods and the accounting cost flow need not be identical. A retailer may sell older units first while using a weighted-average accounting method. The selected method should faithfully represent the entity’s circumstances and be applied consistently to inventories of a similar nature and use.

3.1 Specific identification

Specific identification assigns the actual cost of each item sold and each item remaining. It is appropriate for items that are not ordinarily interchangeable, such as unique artworks, customized construction projects, or high-value automobiles with separately identifiable costs. It is inappropriate when large numbers of interchangeable units are routinely traded and selection could manipulate profit.

3.2 First-in, first-out (FIFO)

FIFO assumes that the earliest costs are assigned to the earliest sales. Ending inventory therefore tends to reflect more recent costs. During rising prices, FIFO usually produces lower cost of goods sold, higher ending inventory, and higher reported gross profit than weighted average, although the exact result depends on the pattern of purchases and sales.

3.3 Weighted-average cost

Weighted average assigns a common average cost per unit to units available for sale. Under a periodic system:

The formula assumes homogeneous or interchangeable units and uses the total units and total costs available during the period. Under a perpetual system, a new average is calculated after each purchase; this is often called the moving-average method.

Worked Example 2: FIFO and weighted average

A retailer has the following transactions:

If 250 units are sold, 150 units remain.

FIFO: The 250 units sold consist of 100 units at $10 and 150 units at $12:

• Cost of goods sold = ($100 × 10) + ($150 × 12) = $2,800
• Ending inventory = 50 units at $12 plus 100 units at $15 = $2,100

Weighted average:

• Cost of goods sold = 250 × $12.25 = $3,062.50
• Ending inventory = 150 × $12.25 = $1,837.50

The two methods allocate the same $4,900 between cost of goods sold and ending inventory, but they report different timing of expense recognition.

3.4 Periodic and perpetual systems

A periodic system determines ending inventory through a physical count and calculates cost of goods sold at period-end. A perpetual system updates inventory records after each purchase and sale. Perpetual systems provide timely information and support reorder decisions, but they require reliable transaction capture and ongoing reconciliation.

The inventory equation is:

This identity assumes no separate adjustments for returns, shrinkage, write-downs, or production transfers. Where such items exist, they must be recorded explicitly.

4. Lower of Cost and Net Realisable Value

Inventory is measured at the lower of cost and net realisable value (NRV). NRV is the estimated selling price in the ordinary course of business less the estimated costs of completion and the costs necessary to make the sale.

NRV is an entity-specific estimate of recoverable selling value. It is not the same as fair value, which is a market-based measurement. NRV should reflect current evidence, including selling prices, damage, obsolescence, expected completion costs, and selling arrangements.

Worked Example 3: Inventory write-down

Inventory has a recorded cost of $80,000. Its estimated selling price is $78,000, completion costs are $3,000, and selling costs are $2,000.

Because $73,000 is lower than cost of $80,000, inventory is reported at $73,000 and a $7,000 write-down is recognized as an expense, unless another applicable standard requires a different treatment.

If circumstances that caused a previous write-down subsequently improve, the write-down may be reversed to the extent permitted by the applicable reporting framework. The revised amount cannot exceed the cost that would have been recognized had no write-down occurred.

Applying the rule

The assessment is normally made item by item, or for groups of similar or related items where individual identification is impracticable. It is inappropriate to write down profitable products to offset losses on obsolete products. Estimates must be evidence-based and documented.

5. Estimating Inventory

A physical count and detailed records are preferable. Estimation methods are useful when inventory is lost through fire, records are temporarily unavailable, or interim financial statements are prepared.

5.1 Gross-profit method

The gross-profit method estimates cost of goods sold from sales using an established gross-profit rate.

If the gross-profit rate is expressed as a percentage of sales:

The method assumes that the historical gross-profit relationship remains reasonably representative. It is unsuitable when margins change substantially, product mix shifts, or unusual losses occur.

Example: Goods available for sale cost $120,000. Net sales are $150,000 and the normal gross-profit rate is 30% of sales.

• Estimated cost of goods sold = $150,000 × 70% = $105,000
• Estimated ending inventory = $120,000 − $105,000 = $15,000

A gross-profit rate based on cost rather than sales must not be confused with the rate above. If gross profit is 30% of sales, cost is 70% of sales; if markup is 30% on cost, cost is sales divided by 1.30.

5.2 Retail inventory method

The retail method estimates cost by applying a cost-to-retail ratio to ending inventory at retail value:

The method is practical for retailers with many similar items, but it depends on reliable records of markdowns, markups, returns, and product categories. Modern systems often use barcode and point-of-sale data to improve estimates.

6. Effects on Financial Statements, Tax, and Decisions

Inventory affects several measures:

• Gross profit: Sales less cost of goods sold.
• Current assets: Ending inventory is included in current assets when expected to be realized in the operating cycle.
• Working capital: Inventory contributes to current assets but may be less liquid than cash or receivables.
• Profit margin: Cost-flow choices affect the timing of reported profit.
• Taxable income: Tax rules may differ from financial reporting rules; a lower deductible inventory cost may reduce current taxable profit, but tax consequences depend on legislation.
• Cash flow: Inventory purchases use cash before sales generate cash. Inventory measurement itself is generally non-cash, but write-downs and purchasing decisions affect cash planning.

A useful performance measure is inventory turnover:

where average inventory is commonly approximated as (opening inventory + closing inventory) ÷ 2. The ratio is meaningful only when measured consistently and interpreted alongside industry conditions. A high turnover may indicate efficient stock management, but it may also signal understocking. A low turnover may indicate weak demand, excessive purchasing, or deliberate buffering against supply disruption.

7. Internal Control and Governance

Inventory is vulnerable to theft, damage, obsolescence, unauthorized purchases, recording errors, and deliberate earnings manipulation. Effective controls include:

1. Segregating purchasing, receiving, custody, recording, and payment duties.
2. Using sequential purchase orders, receiving reports, and sales documents.
3. Performing independent physical counts and investigating differences.
4. Reconciling perpetual records with the general ledger.
5. Reviewing aged, damaged, returned, and slow-moving items.
6. Restricting access to warehouses and inventory systems.
7. Testing cut-off around the reporting date.
8. Approving write-offs and write-downs independently.
9. Monitoring unusual margin, turnover, or adjustment patterns.

Management has an ethical duty not to delay necessary write-downs, count goods that do not belong to the entity, or manipulate estimates to meet targets. Auditors should obtain evidence about existence, completeness, rights and obligations, valuation, and presentation. Inventory held for another party, goods in transit, and consignment stock require particular attention.

8. Technology, Data, and Contemporary Practice

Enterprise resource planning systems connect purchasing, warehouse movements, production, sales, and accounting. Barcodes, radio-frequency identification, cycle counting, and automated reorder points can improve accuracy and reduce manual work. Continuous monitoring can identify negative quantities, unusual adjustments, duplicate receipts, and margin anomalies.

Artificial intelligence can assist with demand forecasting, obsolescence risk scoring, and exception detection. However, AI outputs do not replace management responsibility. Forecasts may reproduce biased or incomplete data, and automated recommendations can cause overstocking or stockouts if demand conditions change. Sound governance requires documented data sources, human review, access controls, model monitoring, and an audit trail.

Contemporary supply-chain disruptions also make valuation more judgmental. Freight volatility, geopolitical restrictions, climate events, product recalls, and rapid technological change can affect both cost and NRV. Entities should update estimates using current evidence rather than relying mechanically on historical margins.

9. Applied Case: Meridian Home Appliances

This is an illustrative case. Meridian Home Appliances sells refrigerators and small kitchen appliances. It uses a perpetual inventory system and FIFO for financial reporting. At year-end, 400 refrigerators are recorded at a cost of $620 each. A new model has reduced the expected selling price of the older model.

Background and problem

The older refrigerators can be sold for $650 each. Packaging and delivery costs necessary to make the sale are estimated at $20 per unit. A sales commission of $15 per unit is also payable. Management initially proposes retaining inventory at recorded cost because the goods are physically present and undamaged.

Analysis

NRV per unit is:

Cost is $620 per unit, so the required write-down is $5 per unit. For 400 units:

The inventory should be reported at $246,000 rather than $248,000, assuming no other relevant evidence changes the estimate.

The finance team also discovers that 30 refrigerators received before year-end were excluded from the count because the receiving report was processed two days late. If control had passed to Meridian before year-end, those units must be included. Conversely, goods shipped to a customer under terms transferring control after delivery should not be removed prematurely.

Approach and outcome

Meridian documents current selling prices, completion and selling costs, the inventory count, and cut-off testing. It records the $2,000 write-down, investigates the omitted receipts, and improves the receiving system by matching purchase orders, receiving reports, and supplier invoices electronically.

Learning points

The case demonstrates that physical existence does not establish recoverable value, and a reliable count does not by itself establish correct ownership or cut-off. Inventory measurement requires both cost records and current NRV evidence. It also shows why operational controls and accounting judgments are interdependent.

10. Limitations and Professional Judgment

No inventory method eliminates judgment. FIFO and weighted average may produce different reported results even when physical operations are unchanged. NRV estimates depend on uncertain selling prices and costs. Gross-profit and retail methods provide expedient estimates but can conceal product-level losses. Historical cost may not reflect replacement cost or strategic scarcity. Comparisons between entities therefore require knowledge of accounting policies, product mix, inflation, and supply-chain conditions.

Professional judgment should be transparent, consistently applied, supported by evidence, and reviewed for bias. Material assumptions should be communicated in financial statement disclosures where required. The objective is not to produce the most favorable result, but to represent inventory faithfully and support informed decisions.

Chapter Summary

Inventory is an asset held for sale, production, or consumption in production. Its cost includes purchase costs, conversion costs, and other costs necessary to bring it to its present location and condition. Cost-flow methods include specific identification, FIFO, and weighted average; the choice affects the timing of cost of goods sold and profit but not the total cost available for allocation.

Inventory is reported at the lower of cost and NRV. NRV equals expected selling price less completion and selling costs. Write-downs recognize losses when inventory is no longer recoverable at cost. Gross-profit and retail methods estimate inventory when detailed records or a physical count are unavailable, but their reliability depends on stable margins and accurate underlying data.

Inventory measurement affects profit, assets, tax, liquidity analysis, and management decisions. Strong controls address existence, completeness, ownership, valuation, cut-off, and unauthorized adjustments. Technology improves visibility and monitoring, but automated and AI-supported systems require human oversight, reliable data, and clear accountability.

Key Terms

Inventory: Assets held for sale, in production for sale, or consumed in production.

Cost of goods sold: The cost assigned to inventory sold during a period.

Cost of goods available for sale: Opening inventory plus purchases and eligible costs.

Specific identification: Assigning the actual cost of identifiable items.

FIFO: A cost-flow assumption assigning earliest costs to earliest sales.

Weighted average: A method assigning a common average cost to interchangeable units.

Periodic inventory system: A system that determines inventory and cost of goods sold at period-end.

Perpetual inventory system: A system that updates inventory records continuously.

Conversion costs: Direct labour and allocated production overhead.

Normal capacity: Expected production level over several periods under normal conditions.

Net realisable value: Selling price less completion and selling costs.

Write-down: Reduction of inventory carrying amount when recoverable value declines.

Gross-profit method: An estimation method using an expected gross-profit rate.

Retail method: An estimation method applying a cost-to-retail ratio.

Inventory turnover: Cost of goods sold divided by average inventory.

Consignment inventory: Goods held by one party but owned by another.

Shrinkage: Inventory loss from theft, damage, error, or unexplained shortage.

Cut-off: Recording transactions in the correct accounting period.

Review Questions

#### 5 Short Answer Questions

1. What costs are normally included in inventory cost?
2. Distinguish FIFO from weighted-average costing.
3. Define net realisable value.
4. Why is recoverable sales tax normally excluded from inventory cost?
5. Identify two controls over physical inventory.

#### 5 Long Answer Questions

1. Explain how inventory measurement affects the statement of profit or loss and the statement of financial position.
2. Compare specific identification, FIFO, and weighted-average methods, including their appropriate uses.
3. Explain the lower-of-cost-and-NRV rule and the treatment of subsequent recovery in value.
4. Describe the gross-profit and retail methods of inventory estimation and their limitations.
5. Discuss ethical and governance risks associated with inventory valuation.

#### 3 Analytical / Application Questions

1. A company has goods available for sale costing $96,000 and net sales of $120,000. If the gross-profit rate is 25% of sales, estimate cost of goods sold and ending inventory.
2. Analyze how rising purchase prices may affect FIFO and weighted-average profit, inventory, and tax measures.
3. Design an inventory-control process for a retailer using barcodes, perpetual records, cycle counts, and independent review. Explain how each control addresses a specific risk.

Multiple Choice Questions with Answers

Question 1

Which item is normally included in inventory cost?

A. Recoverable sales tax

B. Abnormal production waste

C. Freight required to bring goods to the warehouse

D. General advertising expense

Correct Answer: C. Freight required to bring goods to the warehouse

Question 2

Under FIFO, which costs are generally assigned first to cost of goods sold?

A. Most recent purchase costs

B. Earliest purchase costs

C. The highest costs only

D. The lowest costs only

Correct Answer: B. Earliest purchase costs

Question 3

Inventory cost is $80,000, estimated selling price is $78,000, completion costs are $3,000, and selling costs are $2,000. What is the required carrying amount?

A. $73,000

B. $75,000

C. $78,000

D. $80,000

Correct Answer: A. $73,000

Question 4

Under a periodic weighted-average method, average cost per unit equals:

A. Ending inventory divided by sales units

B. Total cost available divided by total units available

C. Purchases divided by units sold

D. Sales revenue divided by ending units

Correct Answer: B. Total cost available divided by total units available

Question 5

If ending inventory is overstated, assuming sales revenue is unchanged, the immediate effect is generally:

A. Cost of goods sold overstated and profit understated

B. Cost of goods sold understated and profit overstated

C. Both cost of goods sold and profit understated

D. No effect on profit

Correct Answer: B. Cost of goods sold understated and profit overstated

Question 6

Goods held on consignment for another entity are generally reported as inventory by:

A. The consignee only

B. Neither party

C. The consignor until control passes

D. The warehouse security provider

Correct Answer: C. The consignor until control passes

Question 7

Goods available for sale cost $120,000. Net sales are $150,000 and gross profit is 30% of sales. Estimated ending inventory is:

A. $10,000

B. $15,000

C. $30,000

D. $45,000

Correct Answer: B. $15,000

Question 8

Which control most directly addresses inventory cut-off?

A. Comparing year-end receiving and shipping documents with accounting dates

B. Increasing advertising expenditure

C. Changing from FIFO to average cost

D. Reducing warehouse lighting

Correct Answer: A. Comparing year-end receiving and shipping documents with accounting dates

Question 9

Inventory turnover is calculated as:

A. Sales divided by ending inventory

B. Cost of goods sold divided by average inventory

C. Gross profit divided by purchases

D. Purchases divided by sales

Correct Answer: B. Cost of goods sold divided by average inventory

Question 10

Which statement about AI-based inventory forecasting is most appropriate?

A. It eliminates the need for management judgment

B. It guarantees accurate NRV estimates

C. It requires reliable data, monitoring, and human oversight

D. It replaces physical inventory counts in all circumstances

Correct Answer: C. It requires reliable data, monitoring, and human oversight