FIFO vs LIFO: Inventory Valuation Methods

Understanding Inventory Valuation Methods

Your choice of inventory valuation method affects both profits and taxes. FIFO (First-In, First-Out) and LIFO (Last-In, First-Out) are two fundamental accounting methods that determine the order in which you record inventory costs. The choice isn't arbitrary—it impacts your net income, tax liability, and balance sheet. This guide breaks down both methods, their advantages, and which is best for your business.

What is FIFO (First-In, First-Out)?

FIFO assumes the oldest inventory is sold first. When you purchase inventory in multiple batches at different prices, FIFO treats the oldest/cheapest items as sold first, leaving the newest/more expensive items in inventory. This method matches the physical flow of most businesses—you naturally sell older stock first (especially for perishables and electronics with shorter shelf lives).

FIFO Example

What is LIFO (Last-In, First-Out)?

LIFO assumes the newest inventory is sold first. When calculating COGS, LIFO uses the most recent purchase prices, leaving the oldest/cheapest inventory on the balance sheet. While this doesn't match how most businesses actually sell inventory, it provides significant tax advantages during inflationary periods.

LIFO Example

Key Difference: FIFO shows $1,600 COGS and $2,000 ending inventory. LIFO shows $2,000 COGS and $1,600 ending inventory. In this example, LIFO's higher COGS results in lower profit and lower taxes.

Direct Comparison: FIFO vs LIFO

FIFO vs LIFO: Advantages & Disadvantages

Impact of Inflation on Both Methods

Inflation is the critical factor determining which method benefits you most.

During Inflation (Rising Prices)

• FIFO: Reports higher profits, attracts investors, but triggers higher taxes
• LIFO: Reports lower profits, saves taxes, improves cash flow

During Deflation (Falling Prices)

• FIFO: Reports lower profits, lower tax savings
• LIFO: Reports higher profits, higher taxes

During Stable Prices (No Inflation)

• FIFO & LIFO: Both produce identical results

Which Method for Your Business?

Use FIFO If:

• You sell perishable goods (food, cosmetics, pharmaceuticals)
• You have products with expiration dates
• Your products become obsolete quickly (tech, fashion)
• You operate internationally (IFRS-required)
• You want to maximize reported profits (investor relations)
• You prefer simpler accounting (matches physical flow)
• Prices are relatively stable

Use LIFO If:

• You operate in the US (LIFO not allowed internationally)
• You experience significant price inflation
• Reducing tax liability is a priority
• You can handle more complex tracking
• You want to match current costs with current revenues
• Improving cash flow (via tax savings) matters more than reported profits

Important Accounting Rules

IRS Requirements

• Once selected, you must use the same method every year—you cannot switch between FIFO and LIFO to minimize taxes in different years
• Changing methods requires IRS approval (Form 3115 Accounting Method Change)
• If you don't explicitly choose a method, the IRS assumes FIFO

International Rules (IFRS)

• LIFO is prohibited under IFRS (international accounting standards)
• FIFO, Weighted Average, and Specific Identification are allowed
• If you operate internationally or plan to go public, choose FIFO

Real-World Tax Savings Example

Scenario: You're a seller with inventory cost inflation of 10% annually. Your sales are $500,000, COGS is $300,000 at beginning prices.

Result: LIFO saves $7,500 in taxes annually in this example. Over 5 years, that's $37,500 in tax savings—significant cash flow improvement.