The Income Statement — What a Company Earned

The balance sheet froze the company at an instant. The income statement (also called the profit-and-loss statement, or P&L) is the movie of what happened between two instants: how much the company sold, what it cost to sell it, and what survived as profit. It reads top to bottom like a series of deductions — start with sales, subtract costs in layers, and arrive at the famous “bottom line.” This lesson walks down that waterfall one line at a time and shows you why each layer of profit tells a different story.

Revenue — the top line

Analogy. Revenue is the water entering at the top of a series of filters. Lots pours in; by the time it trickles out the bottom as profit, several layers have taken their cut. Everything below depends on how much entered at the top — which is why revenue is called the top line.

Definition. Revenue (or sales, or turnover) is the total value of goods and services a company sold during the period, before any costs are subtracted. Crucially, revenue is recorded when the sale is earned — when the product ships or the service is delivered — not necessarily when cash arrives. Sell $1M of goods on 30-day credit terms today and you book $1M of revenue today, even though the cash lands next month. (That timing gap is exactly why the cash-flow statement exists — next lesson.)

Misconception. “Revenue is the money in the bank.” No — revenue is sales earned, recognised on delivery. A company can report soaring revenue while its bank balance shrinks, if customers are slow to pay. Revenue is an accounting event; cash is a separate fact.

Gross profit — revenue minus the cost of making the thing

Definition. Cost of goods sold (COGS) — also called cost of sales — is the direct cost of producing what was sold: raw materials, factory labour, the components inside the product. Subtract it from revenue and you get gross profit:

$\text{Gross Profit} = \text{Revenue} - \text{COGS}$

The gross margin expresses this as a percentage:

$\text{Gross Margin} = \frac{\text{Gross Profit}}{\text{Revenue}}$

Worked example. A gadget company sells $1,000M of gadgets that cost $600M in parts and assembly. Gross profit = 1,000 − 600 = $400M; gross margin = 400 / 1,000 = 40%. Forty cents of each sales dollar survives the cost of making the product — before any other expense.

Why gross margin reveals the business model. A luxury-goods house might run a 70% gross margin (cheap to make, dear to buy); a supermarket might run 25% (razor-thin markups, huge volume). Gross margin is the cleanest single readout of pricing power — how much more customers pay than it costs to make the thing.

Misconception. “COGS includes all the company’s costs.” No — COGS is only the direct cost of the goods sold. Salaries for office staff, marketing, R&D, and the CEO’s pay are not in COGS; they come out at the next layer. Mixing them up overstates COGS and understates gross profit.

Operating profit — minus the cost of running the company

Definition. Below gross profit sit the operating expenses (OpEx) — the costs of running the business that aren’t tied directly to a unit of product:

• SG&A — selling, general and administrative: salaries, marketing, rent, office costs.
• R&D — research and development.
• Depreciation and amortization — the spreading of a big asset’s cost over its useful life (more below).

Subtract operating expenses from gross profit and you reach operating income (also called EBIT — earnings before interest and taxes):

$\text{Operating Income (EBIT)} = \text{Gross Profit} - \text{Operating Expenses}$

Worked example. From $400M gross profit, the gadget company spends $150M on SG&A, $80M on R&D, and $20M on depreciation — $250M of operating expenses. Operating income = 400 − 250 = $150M; operating margin = 150 / 1,000 = 15%. This is the profit from the core business operations, before the financing and tax departments get involved.

Depreciation and amortization — the non-cash cost

Analogy. Buy a $50,000 delivery van expected to last 5 years. It would be misleading to record a $50,000 expense in year one and zero afterwards — the van helps earn money for all five years. So accountants spread the cost: $10,000 of depreciation per year. The cash left in year one (you already paid for the van), but the expense is recognised gradually to match the van’s use.

Definition. Depreciation spreads the cost of a tangible asset (machines, vehicles, buildings) over its useful life; amortization does the same for intangibles (patents, software). Both are non-cash expenses — they lower reported profit without any cash leaving in that period. This single fact is the seed of the whole gap between profit and cash, and it’s why EBITDA (coming up) adds them back.

Net income — the bottom line

Definition. Below operating income come the items outside core operations:

• Interest expense — the cost of the company’s debt.
• Taxes — the government’s slice.
• Non-operating / one-off items — gains or losses from selling a division, lawsuit settlements, write-downs.

After all of these, you reach net income — the bottom line, the profit that belongs to shareholders:

$\text{Net Income} = \text{Operating Income} - \text{Interest} - \text{Taxes} \pm \text{One-offs}$

Worked example — the full waterfall. Continuing the gadget company:

Eight cents of every sales dollar survived the whole gauntlet. The three margins — 40%, 15%, 8% — each diagnose a different layer: gross is about making the product, operating about running the company, net about the whole machine including debt and tax.

Misconception. “Net income is the cash the company made this year.” Famously not. Net income includes non-cash expenses (depreciation), counts sales not yet collected (revenue on credit), and excludes cash spent on assets (capital expenditure isn’t an expense — it’s depreciated over years). A company can report record net income and run out of cash. “Profit is an opinion; cash is a fact” — and the next lesson is about that fact.

The three margins — three different diagnoses

Each margin answers a distinct question:

A company with a fat gross margin but a thin operating margin is making its product cheaply but spending heavily to run itself (think a high-R&D tech firm). One with a healthy operating margin but a poor net margin is being eaten alive by interest (too much debt) or taxes. Reading the three together is far more revealing than any one alone.

EBIT and EBITDA — the cousins you’ll meet again

Two acronyms haunt every valuation conversation, so meet them now:

• EBIT = Earnings Before Interest and Taxes = operating income. Strips out financing (interest) and tax to compare the operating performance of companies with different debt loads and tax situations.
• EBITDA = EBIT + Depreciation and Amortization added back. Strips out the non-cash D&A on top, giving a rough proxy for operating cash generation.

Worked example. Gadget company: EBIT = $150M; add back $20M of depreciation → EBITDA = $170M. EBITDA is popular because it’s capital-structure-neutral and non-cash-neutral — handy for comparing a debt-free firm to a leveraged one. But beware: EBITDA pretends depreciation isn’t a real cost, which flatters capital-heavy businesses whose machines genuinely wear out. Charlie Munger memorably dismissed it as “nonsense earnings” for exactly that reason. It’s a useful comparison tool, not a measure of true profit.

A mixed recap pulling from the whole lesson:

Key Takeaways