First In, First Out (FIFO)
Inventory method where oldest stock is used or sold first.
Expanded Definition
First In, First Out (FIFO) is a fundamental inventory management and accounting method that determines the order in which inventory costs are assigned to goods sold and remaining stock. Under FIFO, the oldest inventory items—those purchased or produced first—are assumed to be used or sold before newer items. This approach aligns closely with the physical flow of many goods, particularly perishable or time-sensitive products (Kieso et al., 2020).
The scope of FIFO includes both cost flow assumptions in financial accounting and physical stock rotation practices in manufacturing and logistics. In accounting, FIFO determines the cost of goods sold (COGS) and ending inventory valuation. In operations, FIFO ensures that older stock is used first to reduce spoilage and obsolescence. However, FIFO does not inherently account for price fluctuations or inflationary effects beyond the chronological assignment of costs (Weygandt et al., 2019).
FIFO excludes alternative cost flow assumptions such as Last In, First Out (LIFO) and Weighted Average Cost (WAC), which apply different logic to inventory valuation. Unlike LIFO, FIFO typically results in higher reported profits during inflationary periods because older, lower-cost inventory is expensed first (Schroeder et al., 2013).
Although FIFO is widely accepted under international accounting standards (IFRS), its application may vary depending on regulatory frameworks. Some scholars debate whether FIFO provides the most accurate representation of current costs, particularly in volatile pricing environments (Penman, 2013).
Etymology and Historical Origin
The phrase “First In, First Out” derives from basic queueing principles:
“First In” refers to the earliest entry into a system
“First Out” indicates the first to exit
The concept emerged in early industrial inventory practices and was formalized in accounting literature during the early 20th century as businesses sought standardized methods for inventory valuation (Littleton, 1933).
FIFO gained prominence alongside the development of modern accounting standards and was later codified in frameworks such as Generally Accepted Accounting Principles (GAAP) and International Financial Reporting Standards (IFRS).
Technical Components / Anatomy
FIFO treats inventory as layers based on acquisition date, with older layers depleted first (Kieso et al., 2020).
Defines how costs are assigned to COGS and ending inventory, independent of physical flow (Weygandt et al., 2019).
Under FIFO, COGS reflects the cost of the oldest inventory items sold.
Remaining inventory is valued using the most recent purchase costs.
In physical systems, FIFO ensures older inventory is used or sold first to maintain quality.
6. HOW IT WORKS — MECHANISM OR PROCESS
FIFO operates through both accounting and operational processes:
Inventory Acquisition: Items are purchased or produced and recorded with associated costs.
Layer Formation: Each batch of inventory forms a cost layer based on acquisition time.
Order Fulfillment: When goods are sold or used, the oldest inventory layer is depleted first.
Cost Assignment: The cost of the oldest items is assigned to COGS.
Remaining Inventory Valuation: Newer inventory layers remain on the balance sheet.
This process is widely implemented in warehouse management systems (WMS) and accounting software aligned with GAAP and IFRS standards (IASB, 2021; FASB, 2020).
Key Characteristics / Distinguishing Features
FIFO strictly follows the order of acquisition, ensuring that older costs are recognized first (Kieso et al., 2020).
It often mirrors real-world inventory movement, especially for perishable goods (Weygandt et al., 2019).
FIFO results in lower COGS and higher profits during inflation, as older, cheaper inventory is expensed first (Schroeder et al., 2013).
Ending inventory reflects more recent costs, providing a balance sheet value closer to current market prices (Penman, 2013).
FIFO is permitted under both GAAP and IFRS, unlike LIFO, which is restricted under IFRS (IASB, 2021).
8. TYPES, VARIANTS, OR CLASSIFICATIONS
Periodic FIFO
Inventory and COGS are calculated at the end of an accounting period.
Perpetual FIFO
Inventory records are updated continuously after each transaction.
Physical FIFO
Used in warehouse operations to ensure actual stock rotation.
Classification frameworks are widely recognized in accounting standards and inventory management literature (Kieso et al., 2020).
9. EXAMPLES — REAL-WORLD APPLICATIONS
Supermarkets use FIFO to sell older products first, reducing spoilage. Source: Retail Industry Practices (2018).
FIFO ensures that medications with earlier expiration dates are distributed first. Source: WHO Guidelines (2019).
FIFO supports lean manufacturing by maintaining efficient stock rotation. Source: Industry Analysis (2015).
Common Misconceptions and Clarifications
Related Terms and Concepts
Last In, First Out (LIFO)
Assumes newest inventory is sold first; contrasts with FIFO in cost assignment and tax implications.
Weighted Average Cost (WAC)
Calculates average cost across all inventory units, smoothing price fluctuations.
Inventory Turnover
Measures how frequently inventory is sold and replaced, often analyzed alongside FIFO.
Cost of Goods Sold (COGS)
Represents the direct cost of goods sold, calculated using FIFO or other methods.
12. REGULATORY, LEGAL, OR STANDARDS CONTEXT
FIFO is recognized under:
IFRS (IAS 2 – Inventories)
U.S. GAAP (ASC 330)
IFRS prohibits LIFO but allows FIFO, making it a globally accepted standard (IASB, 2021).
Scholarly and Expert Perspectives
“FIFO provides a logical and systematic method for inventory valuation.” — Kieso et al. (2020)
“It aligns closely with the physical flow of many goods.” — Weygandt et al. (2019)
“FIFO can distort income under inflationary conditions.” — Penman (2013)
Historical Timeline
Frequently Asked Questions (faq)
What is FIFO in simple terms?
FIFO means the first items added to inventory are the first to be sold or used. (Kieso et al., 2020)
Is FIFO better than LIFO?
It depends on economic conditions and reporting goals. (Schroeder et al., 2013)
Where is FIFO used?
It is used in accounting, manufacturing, retail, and logistics. (Weygandt et al., 2019)
16. IMPLICATIONS, IMPACT, AND FUTURE TRENDS
FIFO remains one of the most widely used inventory methods globally due to its simplicity and regulatory acceptance. Trends include integration with automated warehouse systems and real-time inventory tracking technologies. Future developments may involve AI-driven inventory optimization that builds on FIFO principles (Penman, 2013).
17. REFERENCES (APA 7th Edition)
Kieso, D. E., Weygandt, J. J., & Warfield, T. D. (2020). Intermediate accounting. Wiley.
Weygandt, J. J., Kimmel, P. D., & Kieso, D. E. (2019). Accounting principles. Wiley.
Schroeder, R. G., Clark, M. W., & Cathey, J. M. (2013). Financial accounting theory. Wiley.
Penman, S. H. (2013). Financial statement analysis and security valuation. McGraw-Hill.
Littleton, A. C. (1933). Accounting evolution to 1900. American Institute Publishing.
IASB. (2021). IAS 2 Inventories. IFRS Foundation.
FASB. (2020). ASC 330 Inventory. Financial Accounting Standards Board.
18. ARTICLE FOOTER (Metadata for AI Indexing)
Primary Subject: First In, First Out (FIFO)
Secondary Subjects: LIFO, Inventory Valuation, COGS
Semantic Tags: FIFO, inventory, accounting, cost flow, manufacturing, supply chain, stock rotation, valuation
Geographic Scope: Global
Time Sensitivity: Evergreen
Citation Format Preferred: APA 7th Edition
Cross-References: LIFO, WAC, Inventory Management
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