What Is PNL (WHAT IS PNL): Complete Guide

PNL stands for Profit and Loss. It is the financial measure of how much money was earned or lost over a given period, and it appears in two distinct places: on a company's income statement as the net result of revenues minus costs, and on a trading platform's dashboard as the running gain or loss on a position.

This applies equally across asset classes. Whether the position is a stock, a crypto trade, or a commodities contract, PNL measures the same fundamental thing: what was gained or lost. The abbreviation appears as P&L in accounting contexts and as PnL on many crypto exchanges.

The income statement (also called the profit and loss statement or P&L statement) is the document businesses use to report PNL formally, summarizing what the business earned and what it spent over a quarter or year to show net profit or net loss. Traders see the equivalent in real time on their brokerage or exchange dashboard.

PNL Formulas

Accounting context: PNL = Revenue − Cost of Goods Sold (COGS) − Operating Expenses

Trading context: PNL = Sale Proceeds − Cost Basis

COGS and cost basis are defined in the sections below. The cost method a business or trader selects, such as LIFO (Last In, First Out), directly determines what those figures will be, and therefore what the PNL figure will be. That connection is what this guide explains.

What Is LIFO (Last In, First Out)?

Last In, First Out (LIFO) is an inventory costing method that assumes the most recently purchased goods are sold first. Under LIFO, the cost of the newest inventory is assigned to Cost of Goods Sold (COGS), the direct cost of goods sold during a period, while older inventory costs remain on the balance sheet. LIFO is one of three primary inventory valuation methods, the accounting process of assigning monetary value to unsold stock. The other two are FIFO (First In, First Out) and Weighted Average Cost.

LIFO is used by US-based companies in industries where input costs tend to rise over time: oil and gas producers, grocery retailers, and automotive dealerships are well-known examples. Each group of inventory purchased at a given price is called an inventory layer. Under LIFO, the most recent layer is always the first one matched against revenue.

LIFO in Two Contexts

Cost basis is the original purchase price of an asset, subtracted from the sale price to calculate trading PNL. Selecting LIFO on a brokerage or crypto exchange changes which lot's cost basis the platform uses, which changes the reported gain and potential tax liability.

In inventory accounting, LIFO belongs to a category called inventory valuation. Businesses must choose one method consistently; the most common options are LIFO, FIFO, and Weighted Average Cost (WAC). For traders, the equivalent selection is called a cost basis accounting method or lot relief method. The trading portfolio worked example shows how this works in practice with real numbers.

How LIFO Affects PNL: The Mechanics Explained

LIFO affects profit and loss by assigning the most recently purchased inventory costs to COGS, which reduces gross profit compared to FIFO in periods of rising prices. This lower reported profit also produces lower taxable income, which is LIFO's primary financial advantage for US businesses.

Gross profit is revenue minus COGS. Net profit (also called net income) is gross profit minus all remaining expenses. The chain from LIFO's cost assignment to the final PNL figure runs as follows:

LIFO PNL Transmission Chain

Revenue − COGS (LIFO) = Gross Profit

Gross Profit − Operating Expenses = Net Profit / PNL

COGS Formula

COGS = Beginning Inventory + Purchases − Ending Inventory

LIFO's effect on PNL is most significant during inflationary periods, when the most recently purchased inventory costs more than older inventory. In deflationary environments, the effect reverses: LIFO assigns lower recent costs to COGS, producing higher gross profit than FIFO in that scenario.

While LIFO lowers taxable income through higher COGS, it comes at a cost to the balance sheet. Ending inventory is recorded at older, lower cost prices, which can significantly understate the true current value of inventory assets during inflationary periods. This trade-off is examined in full in the LIFO reserve section.

LIFO's impact on PNL is visible on the income statement through the COGS line item. Businesses that switch from FIFO to LIFO see their COGS rise and their gross profit fall in the same period, with no change to actual sales revenue.

For traders, switching an exchange setting from FIFO to LIFO changes which purchase lot's cost basis is deducted from sale proceeds. Two identical trades produce different realized PNL figures depending purely on which cost method the platform applies. The business inventory worked example and the trading portfolio worked example show both scenarios with verified numbers.

How to Calculate PNL Using LIFO: The Formulas

Calculating PNL using LIFO requires five formulas and a four-step process. Each formula corresponds to a step in the calculation chain, from identifying which cost to assign through to the final net profit figure.

Formula 1: COGS Under LIFO

COGS = Cost of Most Recently Purchased Units Sold

Formula 2: Gross Profit

Gross Profit = Revenue − COGS (LIFO)

Formula 3: Net PNL (Business)

Net PNL = Revenue − COGS − Operating Expenses − Taxes

Formula 4: Realized PNL (Trading)

Realized PNL = Sale Proceeds − LIFO Cost Basis

Formula 5: General COGS

COGS = Beginning Inventory + Purchases − Ending Inventory

Four-Step LIFO PNL Calculation Process

1. List all purchase lots in chronological order. Record each lot's date, unit quantity, and cost per unit.
2. Identify the LIFO cost. When a sale occurs, the most recently purchased lot is treated as the first one sold. That lot's cost per unit becomes the COGS input.
3. Assign that cost to COGS. Multiply the number of units sold from that lot by the cost per unit. If the sale exceeds that lot's quantity, move to the next most recent lot and repeat.
4. Subtract COGS from Revenue to get Gross Profit. Then subtract operating expenses to reach Net Profit / Net PNL.

The only difference between LIFO and FIFO in this process is Step 2. FIFO uses the oldest lot's cost instead of the most recent. Every other step in the calculation chain is identical.

LIFO PNL Worked Example: Business Inventory

This example walks through a full LIFO PNL calculation for a business that buys inventory across three purchase lots and sells 150 units. Every step is labeled so the result can be traced from COGS to gross profit to net PNL.

Scenario

A company purchases inventory in three lots during the period:

• Lot 1: 100 units at $10 per unit (earliest purchase)
• Lot 2: 100 units at $12 per unit
• Lot 3: 100 units at $15 per unit (most recent purchase)

The company sells 150 units at $20 per unit. Revenue = 150 × $20 = $3,000.

LIFO Calculation Steps

1. Under LIFO, Lot 3 is sold first (most recent). 100 units × $15 = $1,500
2. Lot 3 is exhausted after 100 units. The remaining 50 units come from Lot 2 (next most recent). 50 units × $12 = $600
3. Total COGS (LIFO) = $1,500 + $600 = $2,100
4. Gross Profit = $3,000 Revenue − $2,100 COGS = $900
5. Operating Expenses = $200 (assumed for this example). Net PNL = $900 − $200 = $700
6. Ending Inventory (LIFO) = Lot 1 only: 100 units × $10 = $1,000 (remaining on balance sheet)

LIFO Results Summary

Under LIFO, this business reports a net PNL of $700, COGS of $2,100, and ending inventory of $1,000. The three-way LIFO vs. FIFO vs. WAC comparison uses these same numbers to show how FIFO and Weighted Average Cost produce different results from identical purchase lots.

LIFO PNL Worked Example: Trading and Crypto Portfolio

This example shows how LIFO determines realized PNL on a crypto trade, applying the same calculation mechanics used in stock trades on any brokerage account.

Scenario

An investor builds a Bitcoin position across three purchases:

• Purchase 1: 1 BTC at $30,000
• Purchase 2: 1 BTC at $40,000
• Purchase 3: 1 BTC at $50,000 (most recent)

The investor later sells 1 BTC at $55,000.

LIFO Cost Basis Assignment

1. Under LIFO, the most recently purchased BTC is sold first. Purchase 3 at $50,000 is the LIFO cost basis for this sale.
2. Realized PNL (LIFO) = Sale Price − LIFO Cost Basis = $55,000 − $50,000 = $5,000 gain
3. Remaining holdings: Purchase 1 ($30,000) and Purchase 2 ($40,000) form the unrealized position. These are not taxed until closed.

Under FIFO, the oldest purchase ($30,000) would serve as the cost basis. Realized PNL (FIFO) = $55,000 − $30,000 = $25,000, a substantially larger taxable event.

LIFO vs. FIFO: Trading PNL Comparison

In this rising-price scenario, LIFO produces a realized gain of $5,000 versus FIFO's $25,000. The cost basis method selection alone creates a $20,000 difference in reported gain. In trading, realized PNL on a sold asset is treated as a capital gain (or capital loss) for tax purposes. The method selected determines the size of that gain and therefore the potential tax liability.

Many crypto exchanges (including Coinbase and Kraken) and stock brokerages allow cost basis method selection in account settings. The method you select determines how your realized PNL is calculated and reported on each closed position. For a practical look at how exchanges apply these calculations, see profit and loss calculations for USDT contracts.

📋 Tax Disclaimer

Selecting a cost basis method (LIFO, FIFO, or other) on a brokerage or crypto exchange affects how your realized PNL and capital gains are calculated and reported. Tax treatment of capital gains varies by country, asset class, and holding period. This article provides educational information only. Consult a tax professional for advice specific to your trading activity and jurisdiction.

Realized vs. Unrealized PNL: What Is the Difference?

Realized PNL is the profit or loss confirmed by closing a position or completing a sale. It is a taxable financial event. Unrealized PNL is the gain or loss on a position still held open; it fluctuates with market price and is not subject to tax until the position closes.

LIFO affects realized PNL directly. When a position is closed, LIFO assigns the most recently purchased lot's cost basis to the sale, setting the gain or loss. Unrealized PNL is not affected by cost basis method selection until the trade is actually closed.

On crypto exchanges, these figures typically appear as Closed PNL (realized) and Floating PNL or Open PNL (unrealized). The concept is identical regardless of the label a platform uses. For a practical explanation of why a closed position might show a loss while unrealized profit is positive, see why closed P&L shows a loss when unrealized profit is positive.

Understanding take profit and stop loss orders in spot trading is also relevant here, since executing those orders is what converts unrealized PNL into realized PNL.

LIFO vs. FIFO vs. Weighted Average Cost: Side-by-Side Comparison

In an inflationary environment, LIFO produces the lowest gross profit and net PNL of the three methods, FIFO produces the highest, and Weighted Average Cost falls between them. The table below shows this difference using the same three-lot inventory scenario from the business inventory worked example above.

FIFO Calculation (same inputs as the LIFO example)

FIFO (First In, First Out) assumes the oldest inventory is sold first, assigning the lowest historical costs to COGS in an inflationary environment.

• Lot 1 (oldest, $10): 100 units × $10 = $1,000
• Lot 2: 50 units × $12 = $600
• COGS (FIFO) = $1,600
• Gross Profit (FIFO) = $3,000 − $1,600 = $1,400

Weighted Average Cost (WAC) Calculation

Weighted Average Cost (also called AVCO or the Average Cost Method) calculates COGS using the average cost of all inventory available for the period.

• Total inventory cost: (100 × $10) + (100 × $12) + (100 × $15) = $3,700
• Total units: 300
• Average cost per unit: $3,700 ÷ 300 = $12.33 (rounded)
• COGS (WAC): 150 units × $12.33 = $1,850
• Gross Profit (WAC) = $3,000 − $1,850 = $1,150

Three-Way Comparison Table

In an inflationary environment, LIFO produces the lowest gross profit and net PNL because it assigns the highest recent costs to COGS. FIFO produces the highest reported profit. Weighted Average Cost falls between the two. In deflationary conditions, these positions reverse.

A fourth method, Specific Identification, tracks the actual cost of each individual item sold and is practical only for businesses selling high-value unique items like vehicles, jewelry, or real estate. In brokerage accounts, this method is called SpecID or specific lot selection.

Tax Implications: Is LIFO or FIFO Better for Taxes?

In an inflationary environment, LIFO is generally the better choice for reducing current-year taxes. LIFO assigns higher recent costs to COGS, which reduces reported profit and therefore taxable income compared to FIFO.

Using the numbers from the business inventory worked example: LIFO produces net PNL of $700 versus FIFO's $1,200. At a 25% illustrative tax rate, LIFO generates a tax bill of $175 versus FIFO's $300. That $125 difference scales with inventory size and the rate at which input prices are rising.

LIFO does not eliminate taxes. It defers them. The older, cheaper inventory remaining on the balance sheet will eventually be sold and taxed. When prices fall or inventory levels drop (see the LIFO liquidation section for detail on this risk), the deferred tax liability becomes due, sometimes unexpectedly.

The IRS requires companies electing LIFO for tax purposes to also use LIFO for financial reporting. This is the LIFO conformity rule. A business cannot use LIFO for its tax return and FIFO for its published financial statements simultaneously.

For traders, LIFO can reduce capital gains by assigning the highest, most recently purchased cost basis to sold assets. In a rising market, this produces a lower realized gain and therefore a lower capital gains tax liability, as the trading example shows ($5,000 gain under LIFO versus $25,000 under FIFO). Outside the United States, LIFO is not permitted for tax or financial reporting purposes under IFRS. The regulatory section below covers this distinction in full.

📋 Tax Disclaimer

The tax implications of LIFO depend on your specific business structure, cost environment, inflation rate, and jurisdiction. The information in this article is for educational purposes only and does not constitute tax advice. Consult a qualified tax professional or CPA before selecting or changing your inventory costing method or cost basis election.

Advantages and Disadvantages of LIFO

LIFO offers four distinct advantages and five notable disadvantages. The decision to use LIFO depends on whether a business operates in the United States, how often it replenishes inventory, and whether near-term tax reduction or accurate balance sheet reporting matters more to its stakeholders.

Advantages

1. Tax deferral advantage. In inflationary periods, LIFO reduces taxable income by assigning higher recent costs to COGS, deferring tax payments to future periods.
2. Better matching of current costs to current revenues. LIFO pairs the most recent purchase costs against current selling prices, producing a gross profit figure that reflects current market conditions more closely.
3. Protection against inventory profit inflation. Under LIFO, businesses do not report artificial inventory profits when input prices rise, because those rising costs go directly into COGS.
4. Near-term cash flow benefit. Lower tax payments in the current period free up cash for operations and reinvestment.

Disadvantages

1. Balance sheet distortion. Ending inventory is recorded at old, often understated costs. The balance sheet does not reflect current inventory value, which can mislead investors and creditors.
2. LIFO liquidation risk. If inventory levels fall, older cheaper cost layers enter COGS, artificially inflating PNL and triggering unexpected tax liabilities. See the dedicated section on LIFO liquidation risk for a full explanation.
3. Not permitted under IFRS. Businesses reporting internationally or planning to adopt IFRS cannot use LIFO.
4. Complexity and record-keeping burden. LIFO requires tracking multiple inventory layers and costs across accounting periods, increasing administrative complexity.
5. Understated net income for investors. Lower reported profit may make the business appear less profitable to equity investors, even when the cash tax reduction is real and material.

LIFO is most beneficial for US-based businesses with large, frequently replenished inventories in inflationary markets. If a business operates internationally or is considering listing on global stock exchanges, FIFO or Weighted Average Cost may be more appropriate given IFRS restrictions.

LIFO Liquidation: The Hidden PNL Risk

LIFO liquidation occurs when a company sells more inventory units than it purchases during a period. This forces the accounting system to draw on older, cheaper inventory layers to fulfill COGS, producing an artificially lower COGS and a higher gross profit.

⚠️ Warning: LIFO Liquidation Risk

LIFO liquidation can artificially inflate reported PNL and trigger unexpected tax liabilities on previously deferred profits. Business owners using LIFO should monitor inventory levels carefully, particularly at year-end.

LIFO liquidation is not the same as business liquidation, which refers to closing a company. The term refers specifically to the depletion of old LIFO inventory cost layers when current stock runs low.

Numerical illustration: A company holds 50 old units at $10 per unit from Lot 1, its earliest inventory layer. Normally the company replenishes stock regularly, so this layer stays on the balance sheet. In a shortage year, no new inventory arrives and the company sells all 50 units at the current market price of $25. The $10 cost enters COGS instead of a current-market replacement cost of around $22 per unit. Against the $25 selling price, the gross profit on this batch appears as $750 (50 units × $15 apparent margin) rather than the $150 it would be at current replacement costs (50 units × $3 realistic margin). This inflated PNL attracts higher taxes and misrepresents the company's actual profitability to financial statement readers.

To reduce this risk, businesses should plan inventory purchases to maintain sufficient stock levels before period-end. If LIFO liquidation is unavoidable, it must be disclosed clearly in the notes to the financial statements so analysts can adjust their assessments.

LIFO Reserve: Bridging LIFO and FIFO Financial Statements

The LIFO reserve is the difference between a company's inventory value under LIFO and what that inventory value would be under FIFO. Financial analysts use this figure to adjust LIFO-based financial statements to FIFO equivalents, enabling comparisons between companies that use different inventory methods.

Using the numbers from the three-way comparison table: LIFO ending inventory is $1,000 versus FIFO ending inventory of $1,500. The LIFO reserve in this example is $500.

LIFO Reserve Formula

LIFO Reserve = FIFO Inventory Value − LIFO Inventory Value

FIFO Net Income Adjustment Formula

FIFO Net Income ≈ LIFO Net Income + (Change in LIFO Reserve × (1 − Tax Rate))

Analysts apply this adjustment when comparing a LIFO-reporting company against FIFO peers. Without it, the LIFO company appears less profitable and holds less valuable inventory assets on the balance sheet than the same business would under FIFO. This balance sheet distortion is also central to why IFRS prohibits LIFO: the understated inventory values reduce the reliability and cross-company comparability of financial statements.

The LIFO reserve is disclosed in the notes to financial statements. It does not appear as a standalone line item on the face of the balance sheet. This concept is particularly relevant for financial analysts, CPA exam candidates, and investors comparing companies across different inventory accounting methods. It also connects directly to the balance sheet distortion disadvantage of LIFO discussed in the earlier section.

Is LIFO Allowed? GAAP vs. IFRS Regulatory Guide

LIFO is permitted in the United States under US GAAP and prohibited in over 140 countries under IFRS. The difference comes down to how each standard weighs the trade-off between taxable income reduction and balance sheet accuracy.

Under US GAAP (ASC 330): LIFO Is Permitted

US GAAP, which stands for Generally Accepted Accounting Principles, is the set of accounting rules and standards that public and private companies in the United States must follow when preparing financial statements. Under ASC 330 (Inventory), LIFO is a permitted inventory costing method. US companies may elect LIFO for both tax and financial reporting purposes, subject to the LIFO conformity rule described in the tax section above.

Under IFRS (IAS 2): LIFO Is Prohibited

Under IFRS (International Financial Reporting Standards), specifically IAS 2 (Inventories), LIFO is prohibited as an inventory costing method. IFRS prohibits LIFO because it produces balance sheet inventory values that are severely understated in inflationary environments. Because LIFO leaves older, cheaper inventory costs on the balance sheet, a company's assets are understated relative to current market values. This distortion reduces the reliability and cross-company comparability of financial statements, which IFRS standards prioritize. This reasoning connects directly to how LIFO affects PNL through its cost assignment mechanism.

Regulatory Summary

The LIFO conformity rule adds a further constraint in the US: any company using LIFO for tax reporting must also use LIFO for its published financial statements. LIFO and FIFO cannot be mixed across tax and reporting contexts.

If your business operates internationally or is considering adopting IFRS, you must use FIFO or Weighted Average Cost for inventory reporting. Accounting regulations vary by jurisdiction. Consult a qualified accountant or financial advisor for guidance specific to your situation.

Frequently Asked Questions About PNL and LIFO

What does PNL stand for?

PNL stands for Profit and Loss. It is the financial measure of the difference between total revenues or sale proceeds and total costs or expenses over a given period. In trading, PNL appears as the difference between the sale price and the purchase cost (cost basis) of an asset.

What is LIFO in accounting?

LIFO (Last In, First Out) is an inventory costing method that assumes the most recently purchased items are sold first. Under LIFO, the newest inventory costs are assigned to Cost of Goods Sold (COGS), reducing gross profit compared to FIFO in inflationary markets. It is permitted under US GAAP (ASC 330) but prohibited under IFRS (IAS 2).

Does LIFO increase or decrease profit?

In an inflationary environment, LIFO decreases reported profit compared to FIFO. LIFO assigns higher recent costs to COGS, which reduces gross profit and net income. In deflationary conditions, the effect reverses and LIFO produces higher profit than FIFO.

What is the difference between realized and unrealized PNL?

Realized PNL is profit or loss that has been confirmed by closing a trade or completing a sale. It is a taxable event. Unrealized PNL is the paper gain or loss on an open position still held; it changes with market prices and is not taxable until the position is closed.

Is LIFO or FIFO better for taxes?

In inflationary environments, LIFO is typically better for reducing current-year taxes. LIFO assigns higher recent costs to COGS, lowering reported profit and taxable income. This is a tax deferral, not a permanent reduction, and LIFO is only permitted for tax purposes in the United States. Consult a tax professional for advice specific to your situation.

Is LIFO allowed under IFRS?

No. LIFO is prohibited under IFRS (International Financial Reporting Standards), specifically IAS 2 (Inventories). IFRS prohibits LIFO because it produces understated inventory values on the balance sheet in inflationary environments, reducing the reliability and comparability of financial statements across international companies. Only US GAAP permits LIFO.

What is a LIFO reserve?

The LIFO reserve is the difference between a company's inventory value under LIFO and the higher value it would have under FIFO. Financial analysts use the LIFO reserve to adjust LIFO-based financial statements to FIFO equivalents for cross-company comparisons. It is disclosed in the notes to financial statements, not on the face of the balance sheet.

What happens during a LIFO liquidation?

LIFO liquidation occurs when a company sells more inventory than it purchases in a period, forcing older, cheaper inventory cost layers into COGS. This artificially inflates gross profit and net income, creating a misleading picture of profitability and triggering an unexpected tax liability on previously deferred profits.

Who uses LIFO accounting?

LIFO is primarily used by US-based companies in industries where inventory costs are subject to inflation, including oil and gas producers, grocery retailers, and automotive dealerships. It is not available to companies reporting under IFRS, which covers businesses in over 140 countries outside the United States.

What is the difference between LIFO and FIFO?

LIFO assigns the most recent inventory costs to COGS; FIFO assigns the oldest costs. In an inflationary environment, LIFO produces higher COGS, lower gross profit, and lower reported net income than FIFO. FIFO produces higher ending inventory values on the balance sheet. Both methods are permitted under US GAAP; only FIFO is permitted under IFRS.

How does LIFO affect my trading PNL?

When LIFO is selected as the cost basis method on a brokerage or crypto exchange account, the platform uses the price of the most recently purchased lot as the cost basis when calculating realized PNL on a sale. In a rising market, this assigns a higher cost basis to sold assets, reducing the reported realized gain compared to FIFO.

What is a good PNL?

A good PNL depends entirely on context, including goals, risk tolerance, investment horizon, and market conditions. A positive PNL means more was earned than spent; a negative PNL means a net loss occurred. Traders typically evaluate PNL relative to risk taken, using metrics like the risk/reward ratio, rather than as an absolute figure.