FIFO vs LIFO: How Inventory Methods Affect Your Financial Statements
How FIFO Works
Under FIFO, the cost of goods sold on the income statement reflects the oldest (and typically cheapest, during inflation) inventory costs. The remaining inventory on the balance sheet reflects the newest (and most expensive) costs, which more closely approximates current market value.
FIFO is the more intuitive method — it matches the physical flow of inventory for most businesses (you sell old stock before new stock). It’s required under IFRS and allowed under GAAP. Most companies worldwide use FIFO.
How LIFO Works
Under LIFO, cost of goods sold reflects the newest (most expensive, during inflation) inventory costs. This produces higher COGS, lower gross profit, and lower taxable income. The inventory remaining on the balance sheet reflects old, potentially outdated costs — making it a poor indicator of current inventory value.
LIFO is only permitted under GAAP — it’s banned under IFRS. It’s primarily used by U.S. companies (particularly in oil, gas, and commodities) for its tax advantages. The IRS requires companies to use LIFO for financial reporting if they use it for tax purposes (the LIFO conformity rule).
FIFO vs LIFO: Side-by-Side Comparison
| Feature | FIFO | LIFO |
|---|---|---|
| Inventory Flow Assumption | Oldest inventory sold first | Newest inventory sold first |
| COGS (During Inflation) | Lower (uses old, cheaper costs) | Higher (uses new, expensive costs) |
| Gross Profit (During Inflation) | Higher | Lower |
| Taxable Income (During Inflation) | Higher → more taxes | Lower → less taxes |
| Balance Sheet Inventory | Closer to current market value | Understated (old costs) |
| Accounting Standard | GAAP and IFRS | GAAP only (banned under IFRS) |
| Cash Flow Impact | Lower (higher taxes paid) | Higher (lower taxes paid) |
| LIFO Reserve Disclosure | Not applicable | Required in footnotes |
| Common Industries | Retail, food, manufacturing | Oil & gas, chemicals, commodities |
Impact on Financial Statements: An Example
Imagine a company buys 100 units at $10 each, then 100 units at $15 each, and sells 100 units. Under FIFO, COGS = $1,000 (the $10 units). Under LIFO, COGS = $1,500 (the $15 units). The $500 difference flows straight to gross profit and, after taxes, to net income.
At a 25% tax rate, the LIFO company pays $125 less in taxes on this transaction. Scale that across billions in inventory for a large manufacturer, and the tax savings become material — often tens of millions annually. That’s why companies choose LIFO despite the lower reported profit.
The LIFO Reserve: Converting Between Methods
U.S. companies using LIFO must disclose the LIFO reserve — the difference between inventory valued under LIFO and what it would be under FIFO. To convert LIFO financials to FIFO for comparison purposes: add the LIFO reserve to inventory and equity on the balance sheet, and adjust COGS by the change in the LIFO reserve for the period.
This conversion is essential when comparing companies using different inventory methods — a common task in comparable company analysis and cross-border valuation.
Which Method Should Companies Choose?
Companies choose LIFO primarily for tax savings during inflationary periods. If rising costs are the norm for your inputs, LIFO reduces taxable income and preserves cash. Companies choose FIFO when balance sheet accuracy matters more, when operating under IFRS, or when they want to report higher earnings (which can affect stock price and executive compensation).
Key Takeaways
- FIFO produces higher profits and a more accurate balance sheet during inflation. LIFO produces lower taxes and better cash flow.
- LIFO is only allowed under GAAP — banned under IFRS. Cross-border comparisons require LIFO-to-FIFO adjustments.
- The LIFO reserve (disclosed in footnotes) is the key to converting between the two methods.
- The choice between FIFO and LIFO is primarily a tax strategy decision, not an operational one.
- During deflation (falling prices), the effects reverse: FIFO produces lower profits and LIFO produces higher profits.
Frequently Asked Questions
Why is LIFO banned under IFRS?
IFRS bans LIFO because it doesn’t represent the actual physical flow of goods for most businesses and produces balance sheet inventory values that can be severely understated. The IASB considers LIFO a tax optimization tool that distorts financial reporting rather than reflecting economic reality.
Can a company switch from LIFO to FIFO?
Yes, but it’s a significant accounting change that requires restating prior periods and can trigger a large one-time tax bill on the previously deferred LIFO tax savings. Companies occasionally switch when the tax benefits diminish (during deflation) or when they want to align with IFRS for global comparability.
Does FIFO or LIFO better reflect actual inventory costs?
FIFO produces balance sheet inventory values that better reflect current replacement costs. LIFO produces income statement COGS that better reflect current cost of replacing sold inventory. Neither method perfectly captures both dimensions simultaneously — that’s why the LIFO reserve disclosure exists.
How does FIFO vs LIFO affect inventory turnover ratio?
LIFO understates inventory on the balance sheet (because it carries old costs), which artificially inflates the inventory turnover ratio. When comparing turnover across companies, convert LIFO companies to FIFO first using the LIFO reserve for an apples-to-apples comparison.
What is the weighted average cost method?
The weighted average method assigns the same average cost to all units — a middle ground between FIFO and LIFO. It smooths out cost fluctuations and produces COGS and inventory values between FIFO and LIFO extremes. It’s permitted under both GAAP and IFRS and is common for companies with homogeneous inventory.