How to Read an Income Statement: A Step-by-Step Walkthrough

To read an income statement, start at revenue and work down line by line: subtract cost of goods sold to get gross profit, subtract operating expenses to get operating income, then subtract interest and tax to get net income. At each step, calculate the margin and compare it with prior years. The trend in those margins tells you far more than any single year’s profit.

The income statement is the most widely read page of any annual report, and the most often misread. Most people check whether earnings went up and stop there. This walkthrough shows you what each line means, what to calculate and what to watch for.

Where this fits: the income statement is one of the three statements covered in our hub, how to read financial statements. It supplies the margins and profit figures used in Criterion 1 (great business), Criterion 2 (moat) and Criterion 4 (balance sheet) of the Five Criteria.

What Is an Income Statement?

The income statement shows how much a business earned over a period, usually a quarter or a financial year. You will also see it called the profit and loss statement (P&L), the statement of operations or, under IFRS, the statement of profit or loss.

Unlike the balance sheet, which is a photograph of a single day, the income statement is a video of a whole period. That is why one year on its own tells you little. Five to ten years of income statements, side by side, tell you a lot.

Every income statement follows the same logic. Start with what customers paid. Subtract costs one layer at a time. What is left at the bottom belongs to shareholders.

The Worked Example: Company A

We will use Company A, the hypothetical garden-tool maker that appears throughout our financial statements series. All figures are in millions of dollars.

Line	Amount	Margin	What it tells you
Revenue	1,000	100%	Size of the business
Cost of goods sold	(600)	Direct cost of making the product
Gross profit	400	40%	Pricing power and production economics
Selling, general and admin	(150)	Overheads
Research and development	(50)	Investment in future products
Depreciation and amortisation	(50)	Non-cash cost of using assets
Operating income (EBIT)	150	15%	Profit from the core business
Interest expense	(20)	Cost of debt
Pre-tax income	130	13%
Income tax	(30)	About 23% effective rate
Net income	100	10%	The bottom line
Diluted EPS	$2.00	100 divided by 50 million diluted shares

Now let us walk through it.

How to Read an Income Statement, Step by Step

Step 1: revenue, the top line

Revenue (also called sales, net sales or turnover) is the money earned from customers for goods delivered or services performed during the period. It is reported net of returns, discounts and allowances, so it reflects what the company expects to collect, not its list prices.

Growing revenue means the business is winning customers, raising prices or both. Flat or falling revenue needs an explanation. Is the market shrinking, or is the company losing ground? The number alone does not say, but it tells you which question to ask next.

Look at revenue over at least five years. Also check whether growth is organic or bought through acquisitions. The notes and management’s discussion usually split this out.

Step 2: cost of goods sold and gross profit

Cost of goods sold (COGS), or cost of revenue, covers the direct costs of what the company sells. For Company A that means steel, plastic, factory wages and factory overhead. For a software company it means hosting, licences and customer support.

Revenue minus COGS is gross profit. Divide gross profit by revenue and you get the gross margin. Company A’s is 400 / 1,000 = 40%.

Gross margin is often the first place a competitive advantage shows up. A business that can charge more than its cost of production, year after year, usually has something competitors cannot easily copy.

A real example: Apple’s fiscal 2023 annual report showed revenue of about $383 billion and gross profit of about $169 billion, a gross margin of roughly 44%. Apple keeps about 44 cents of each sales dollar before it spends anything on marketing, research or head office. Grocery retailers, by contrast, typically run gross margins in the 20s or low 30s.

Step 3: operating expenses

Operating expenses are the costs of running the business beyond making the product:

• Selling, general and administrative (SG&A): marketing, sales teams, head office, rent and executive pay.
• Research and development (R&D): spending on future products. Rising R&D as a share of revenue can mean reinvestment; falling R&D can flatter profits today at the expense of tomorrow.
• Depreciation and amortisation (D&A): the annual accounting charge for using up long-term assets. It reduces profit, but no cash leaves the business that year. Some companies show D&A as its own line; others spread it inside COGS and SG&A, and you find it on the cash flow statement.

Step 4: operating income (EBIT)

Gross profit minus operating expenses gives operating income, often called EBIT (earnings before interest and taxes). It is the cleanest measure of how the core business performs, before financing choices and tax.

Operating margin is operating income divided by revenue. Company A’s is 150 / 1,000 = 15%. Apple’s operating income in fiscal 2023 was about $114 billion, an operating margin of roughly 30%.

Add D&A back to operating income and you get EBITDA. Company A’s EBITDA is 150 + 50 = 200. EBITDA is useful for measuring debt, which we cover in Criterion 4, but it is not cash flow, because it ignores the capital spending needed to replace worn-out assets.

Step 5: interest, tax and net income

Below operating income come the costs of financing. Interest expense is what the company pays on its debt. Interest income is what it earns on its cash. The result is pre-tax income. Subtract income tax and you reach net income, the bottom line.

Company A’s net income is 100, a net margin of 10%. Apple’s fiscal 2023 net income was about $97 billion, a net margin of roughly 25%.

Watch this section for unusual items: gains on asset sales, restructuring charges, impairments and “other income”. They can make one year’s net income look much better or worse than the business really performed.

Step 6: earnings per share

At the very bottom you will find basic and diluted earnings per share (EPS). EPS is net income divided by the number of shares. Diluted EPS includes shares that could be created from stock options and convertible securities, so it is the more conservative figure. Always use diluted EPS.

Company A’s diluted EPS is 100 / 50 = $2.00. The income statement also shows the diluted share count, which is one of the most useful numbers for judging management. Our plain-English guide to EPS covers the traps.

What the Three Margins Tell You Together

Gross, operating and net margin, read together and over time, tell a story no single figure can.

Pattern	What it usually means
High gross margin, thin operating margin	Strong product economics, but heavy overheads or R&D
Gross and operating margin both rising	Pricing power plus operating leverage: the ideal
Gross margin falling for several years	Competition, rising input costs or weakening pricing power
Operating margin rising, gross margin flat	Cost control or scale benefits
Net margin far above operating margin	One-off gains or unusual financial income: investigate

Philip Fisher, in Common Stocks and Uncommon Profits, put profit margins and the steps a company takes to maintain or improve them near the top of his list of things to investigate. The trend matters more than the level. A gross margin that has risen from 35% to 44% over a decade tells you the business has been strengthening. A shrinking margin tells you the opposite, whatever the headlines say about earnings growth.

The Big Limitation: Net Income Is Not Cash

The income statement uses accrual accounting. Revenue is recorded when earned, not when paid. Costs are recorded when incurred, not when settled. Depreciation reduces profit without any cash leaving. So net income can differ sharply from the cash the business actually produced.

That is why you should never read the income statement alone. The cash flow statement is the check. If net income rises year after year but operating cash flow does not, something needs explaining: customers paying more slowly, inventory piling up, or aggressive revenue recognition.

Buffett makes a related point in his Berkshire Hathaway letters. He has argued for years that Berkshire’s reported GAAP net income, which includes swings in the value of its investments, is a poor guide to how its businesses performed, and he directs shareholders to operating earnings instead. The lesson for any company: understand why the bottom line says what it says.

Normalised Earnings vs Reported Earnings

Benjamin Graham urged investors to look at average earnings over several years rather than a single year. One year can be distorted by a boom, a bust, a big asset sale or a restructuring charge.

A practical way to normalise earnings:

1. Take five to ten years of operating income.
2. Remove clearly one-off gains and losses, but only if they are genuinely one-off.
3. Look at the average operating margin across the cycle.
4. Apply that margin to current revenue.

If Company A earned a 15% operating margin this year but averaged 12% over ten years, its normalised operating income on 1,000 of revenue is closer to 120 than 150. That difference matters a great deal when you value it.

How We Use This in the Five Criteria

The income statement supplies key inputs to three of the Five Criteria:

• Criterion 1, great business: operating income after tax is the numerator of ROIC. We want ROIC of 15% or more for five or more years, and a stable or rising gross margin. See our guide to return on invested capital.
• Criterion 2, durable moat: ten years of gross and operating margins show whether profitability held up through a downturn.
• Criterion 4, sound balance sheet: EBIT divided by interest expense gives interest coverage (house minimum 5x). EBITDA is the denominator of net debt/EBITDA (house maximum 2.0x). Company A scores 7.5x and 1.0x. The full test is in our Criterion 4 hub, how much debt is too much.

The diluted share count also feeds Criterion 3: we want it flat or falling over five years.

Common Mistakes When Reading an Income Statement

• Judging a company on one year. A peak-cycle year makes a mediocre business look excellent.
• Focusing on revenue growth alone. Revenue bought with falling margins or big acquisitions can destroy value.
• Accepting “adjusted” profit without checking. If restructuring costs appear every year, they are a normal cost of doing business.
• Using basic EPS instead of diluted. Basic EPS ignores the dilution from stock options.
• Ignoring where D&A is hidden. If you cannot find it on the income statement, take it from the cash flow statement before calculating EBITDA.
• Never checking cash conversion. Profit that does not turn into cash is a warning, not a result.

Your Next Step

Pull five years of income statements for one company you know and calculate its gross, operating and net margins for each year. Then check whether the profits turned into cash with our guide to how to read a cash flow statement, and see how it all fits together in how to read financial statements.

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About the author: Cameron Hayes is a senior investor relations and finance professional who has worked in IR at Nasdaq Copenhagen-listed companies including Nilfisk and Maersk Drilling. He holds an MSc from Copenhagen Business School and a BCom from the University of Ottawa, and founded Gingernomics to teach individual investors the Five Criteria framework. More about Gingernomics.

The content on Gingernomics is for educational and informational purposes only and does not constitute financial advice. Always do your own research and consult a licensed financial advisor before making any investment decisions. Past performance is not indicative of future results.