Part 3 · Income statement: a report card for a year of business · Lesson 15
Why net income differs from operating profit
Between operating profit and net income come interest, exchange rates, land sales and taxes. Build an eye for what recurs and what happens only once.
QToday's question
News came out that a company's net income tripled from last year. But operating profit is unchanged. Has this company really gotten three times better?
Net income is the core business result with interest, exchange rates, asset sales and taxes added and subtracted. In this lesson we step down the last stairs one by one from operating profit to net income, practicing how to separate profit that will recur from profit that happens only once.
MAPLearning map for this lesson
We build it up in three steps. At the end of each step, a 'Quick check' lets you test your understanding before moving on.
In Lesson 12 we saw the whole staircase of the income statement, and in Lesson 14 we saw operating profit of KRW 1.5 billion, the strength of the core business. The line just below it, 'non-operating −KRW 100 million', we assumed to be interest expense in Lesson 10. The controlling and non-controlling interests from Lesson 11 also reappear at the end of this lesson. How exchange rates reach company profits connects to Economics Lesson 25.
- STEP 1 · Basic conceptsThe three lines below operating profit
Know the order of , , and net income, and explain how Robin Bakery's KRW 1.5 billion becomes KRW 1.2 billion.
- STEP 2 · Understanding the principleThe four faces of non-operating income and expense
Explain what interest, , , and gains and losses on asset disposals are, and why they swing net income.
- STEP 3 · Real-world applicationFiltering out one-offs and earnings quality
Strip out and recalculate recurring profit to judge .
STEP 1The three lines below operating profit
This is the last stretch of the staircase. Follow what gets subtracted as operating profit of KRW 1.5 billion becomes net income of KRW 1.2 billion.
Picture a pay stub. There is the salary set by the company (core income), to which an occasional bonus or money from selling used items is added, and only after loan interest and taxes are subtracted is the money that actually ends up in your account determined. Companies are the same. The you saw in Lesson 14 is the core income that corresponds to salary, and below it, money from outside the core business is added or subtracted.
Revenue and expenses arising outside the core business are grouped together as . In an actual income statement they appear split across several lines such as 'finance income', 'finance costs', 'other income', 'other expenses', and 'equity-method gains and losses'. Adding and subtracting these from operating profit gives 'income before income taxes' (pre-tax profit for short). Finally, subtracting , the tax paid to the state, leaves net income.
Robin Bakery's non-operating income and expense is a very simple case with just one item, KRW 100 million of interest expense. It results from paying about 4.8% interest on KRW 2.1 billion of short- and long-term borrowings, exactly the number we used to calculate the 15x interest coverage ratio in Lesson 10. Corporate income tax has different rates by bracket depending on profit size, and adjustments such as tax credits and carried-forward losses mean the actual burden differs by company and by year. So looking only at net income means looking at a number that is mixed with the 'tax effect' too.
Quick checkRobin Bakery has repaid all its borrowings, so interest expense is zero. If income tax is about 14% of pre-tax profit, roughly how much is net income?
STEP 2The four faces of non-operating income and expense
Non-operating income and expense is not just one thing. Distinguishing four items of different character shows you why net income suddenly jumps or collapses.
Interest: recurs every year as long as there is debt
Most are interest on borrowed money. Unless debt shrinks, it is a cost that will be about the same next year too, and it grows when rates rise. Conversely, a company with a lot of cash earns deposit interest as finance income. What you learned in Economics Lesson 18, that debt-heavy industries are disadvantaged when rates rise, shows up in the financial statements on exactly this line.
Foreign currency translation gain/loss: swings with the exchange rate
A company with debt to be repaid in dollars or money to be received in dollars recalculates the won amount at the closing-date exchange rate. When the won weakens, dollar debt grows in won terms and produces a , while dollar receivables grow and produce a translation gain. Because no money actually changed hands and it is just a re-measurement on the books, it can reverse the other way if the exchange rate returns the next year. This is why the airlines you saw in Economics Lesson 25 post large translation losses when the won weakens.
Share of profit of associates: the portion from stakes in other companies
When a company holds roughly 20–50% of another company's shares and has significant influence over its management, it reflects its ownership share of that company's net income as . It is a weaker relationship than the subsidiaries (control) of Lesson 11, so it is not combined in full; only the share is brought in. It is not money received in cash and it is not the company's core business, but it can recur year after year.
Gain/loss on asset disposals: usually a one-time thing
If a company sells factory land, a building or shares it holds for more than their book value, it records a disposal gain, and for less, a disposal loss. The same land can't be sold twice, so these are mostly one-time gains. Lawsuit settlements, insurance payouts and asset impairment losses (like the goodwill impairment in Lesson 7) are similarly items that don't recur every year.
These are numbers for the fictional company Robin Bakery. Unit: KRW 100 million. Income tax is simply assumed to be about 14% of pre-tax profit (base case 2 ÷ 14). 'Land sale' is a case where a store site was sold for KRW 2.8 billion more than its book value, and 'FX loss' is a case where, assuming imported raw material payables to be settled in dollars and a dollar loan, the weaker won produced a translation loss of KRW 800 million.
In all three situations operating profit is the same KRW 1.5 billion. The bread sold the same and the strength of the core business is unchanged. Yet net income differs by more than sevenfold: KRW 1.2 billion, KRW 3.6 billion and KRW 500 million. This is why judging from net income news alone that "the company got three times better" or "was cut in half" is wrong. If you calculate PER on net income in such years, Robin Bakery in the land-sale year suddenly looks very cheap at a stock price of KRW 9,000 ÷ EPS of KRW 1,800 = PER of 5x. But there is no land left to sell next year.
Common misconceptions
- "Net income rose a lot, so it's good earnings?"
- First check whether operating profit rose too. If operating profit is unchanged and only net income rose, the cause is likely non-operating items, especially one-off gains such as asset sales.
- "A foreign currency translation loss means money was actually lost?"
- It is a remeasurement of book amounts at the closing-date exchange rate, so cash has not actually gone out yet. However, if the debt is repaid with the exchange rate unchanged, it becomes a real loss, so it can't be ignored either. Check in the notes how much dollar debt the company has.
- "Non-operating items are unrelated to the core business, so you can ignore them entirely?"
- Items that recur every year, such as interest expense, really reduce shareholders' share. What you should ignore is not all non-operating items but the ones that 'won't recur'.
Quick checkA company sold shares it held in another company and booked a disposal gain of KRW 5 billion. Can you expect this gain next year too?
STEP 3Filtering out one-offs and earnings quality
Now let's filter them out ourselves. Keeping only recurring profit shows the 'profit you can expect next year too'.
Good means profit comes in from the core business, repeatedly, and as cash. We cover the cash side in Part 4; here we practice sorting out 'does it recur?'. Below is Robin Bakery's hypothetical income statement for the next year (year 4). Operating profit rose a little to KRW 1.6 billion, but net income grew two and a half times to KRW 3 billion. Pick whether each item will recur every year or is just a one-time event.
Reported net income
KRW 3.0 billionAdjusted net income excluding one-offs
-These are fictional numbers. Unit: KRW 100 million. Operating profit 16 + total non-operating 19 = pre-tax profit 35, income tax about 14% (5) → net income 30. Adjusted net income was recalculated by subtracting the items you marked as one-offs from pre-tax profit and applying the same tax rate. 'Robin Flour' is a fictional associate in which Robin Bakery holds 25%.
If you choose the correct answers, adjusted net income is about KRW 1.46 billion. It is less than half of the reported KRW 3.0 billion, but higher than year 3's net income of KRW 1.2 billion. It means the core business really did improve a little, and most of the rest came from selling land. The number with one-offs stripped out becomes a more reliable starting point for calculating EPS and PER in the next lesson.
Real statistics: operating margin and pre-tax margin
The Bank of Korea's Financial Statement Analysis publishes the pre-tax net margin on revenue along with the operating margin on revenue. The difference between the two is the size of the industry average's 'non-operating income and expense'. Tap a bar.
Source: Bank of Korea "2025 Financial Statement Analysis (preliminary)" (published 2026-06-10), 'Key profitability indicators', externally audited companies in 2025. Pre-tax net margin = income before income taxes ÷ revenue.
In 2025, electronics, video and communications equipment had a pre-tax margin of 18.4%, higher than its operating margin of 15.0%. It means non-operating items added profit. Conversely, food products fell from 4.5% to 2.7%, and primary metals from 2.9% to 1.7%. It is a sign that interest, exchange rates and other costs ate into core business profit. If even industry averages differ this much, operating profit and net income can diverge even more at individual companies.
With subsidiaries, net income splits into two lines
In Lesson 11 you saw the scenario where Robin Bakery holds 60% of Robin Coffee. When there is a subsidiary like this, two lines, 'owners of the parent' and 'non-controlling interest', are attached below net income on the consolidated income statement. This is because 40% of what Robin Coffee earns belongs to other shareholders. The number that matters to me as a Robin Bakery shareholder is , and the non-controlling share is . The EPS in the next lesson is also calculated from profit attributable to owners of the parent.
Find it yourself on DART
Open the income statement (or statement of comprehensive income) in the consolidated financial statements under the annual report's III. Financial Matters. 1 Going down below the operating profit line, write down the finance income, finance costs, other income, other expenses and share of profit of associates lines for the current and prior periods. 2 Check income before income taxes, income tax expense and net income, and calculate the difference between operating profit and net income. 3 If the difference is large, look in the notes' 'Other income and other expenses' and 'Finance income and finance costs' tables for details such as gain on disposal of property, plant and equipment, FX translation gain/loss and impairment loss. 4 Write down the line attributable to owners of the parent below net income. Line names can differ slightly by company.
1234Screen: DART, Samsung Electronics annual report 2025.03.11, consolidated income statement (unit: KRW million). Numbers: 1 Operating profit → 2 Non-operating lines such as finance income and costs → 3 Income tax expense → 4 Attributable to owners of the parent. This is an example for learning the route and is not a recommendation to invest.
How to use it in investing
| Earnings headline | What to suspect first | Where to check |
|---|---|---|
| "Operating profit flat, net income surges" | One-offs such as asset sales or valuation gains | Other income note, gain on disposal of property, plant and equipment |
| "Operating profit positive, net loss" | Interest burden, translation losses, impairment losses | Finance costs, foreign currency liabilities note |
| "Net income up, but owners' share down" | Change in the weight of subsidiary profit | Owners/non-controlling attribution lines (Lesson 11) |
| "PER of 4x, record low" | Whether net income includes one-offs | Recalculate with adjusted net income (Lesson 16) |
Not always. What counts as a one-off differs by company and takes judgment. For a company that buys and sells assets every year, disposal gains may be part of the core business, and if a 'one-off' loss repeats for several years, it is no longer a one-off. Looking at several years side by side is the surest way.
Quick checkCompany A has operating profit of KRW 10 billion and net income of KRW 8 billion, and Company B has operating profit of KRW 4 billion and net income of KRW 8 billion. The net income is the same, but whose profit is more reliable?
✓What we learned today
- Operating profit ± non-operating income and expense = income before income taxes, and subtracting income tax expense from that gives net income. For Robin Bakery, that is 15 − 1 = 14, and 14 − 2 = KRW 1.2 billion (in units of KRW 100 million).
- Non-operating income and expense includes interest (recurs the more debt there is), foreign currency translation gain/loss (swings with the exchange rate), share of profit of associates (the portion from stakes in other companies) and gain/loss on asset disposals (usually one-time).
- Even if net income triples from selling land, if operating profit is unchanged the core business has not changed. Using such net income as is when calculating PER makes the company look cheaper than it really is.
- Net income recalculated without one-off items is closer to the profit you can expect next year too. If the gap between operating profit and net income is large, you should be able to explain that gap first.
- When there are subsidiaries, net income is split into owners of the parent and non-controlling interests. My share as a shareholder is the owners' share, and the next lesson's EPS is also calculated from this number.
Dividing net income of KRW 1.2 billion by 2 million shares gives EPS of KRW 600, what one share earns. In the next lesson we find EPS and PER directly in the financial statements and calculate how treasury shares and convertible bonds change EPS.
Quiz5-question quiz
Pick an answer and it's graded right away with an explanation.
Q1. Robin Bakery has operating profit of KRW 1.5 billion, interest expense of KRW 100 million and income tax of KRW 200 million. What is net income?
15 − 1 = KRW 1.4 billion is pre-tax profit, and subtracting income tax of KRW 200 million leaves KRW 1.2 billion.
Q2. Which of the following is least likely to recur every year?
The same land can't be sold twice, so a site-sale gain usually happens only once. Interest expense and interest income recur as long as there is debt and deposits, and equity-method gains recur too if the associate makes a profit.
Q3. Which kind of company sees its foreign currency translation loss grow when the won weakens?
When the won weakens, more won is needed to repay the same dollar debt. That is why a company with a lot of dollar debt books a larger translation loss on the closing date.
Q4. What happens if you calculate PER in a year when net income tripled from a land sale while operating profit stayed the same?
PER is stock price ÷ EPS. If EPS triples because of a one-off gain, PER falls to a third. That gain won't exist next year, so it is an illusion.
Q5. In the Bank of Korea's 2025 Financial Statement Analysis (preliminary), the food products industry had an operating margin of 4.5% and a pre-tax net margin of 2.7%. What does this difference mean?
The pre-tax net margin is a number before income tax, so it has nothing to do with taxes. Being lower than the operating margin means non-operating items such as interest, exchange rates and other costs were a net loss.
NextTerms · Next lesson · Related tools
Revenues and expenses that arise outside the core business. In the income statement they appear as lines such as finance income and finance costs, other income and other expenses, and share of profit of associates. Adding and subtracting them from operating profit gives income before income taxes.
Finance costsFinance costsCosts that arise from borrowing money, such as interest on borrowings and bonds. As long as debt doesn't shrink they recur every year, and they get larger when interest rates rise.
Foreign currency translation gain/lossForeign currency translation gain/lossA bookkeeping gain or loss that arises from remeasuring a company's dollar deposits, receivables and dollar debt at the closing-date exchange rate. Even without cash changing hands, it is reflected in net income as non-operating gain or loss. A company with a lot of dollar debt books a loss when the exchange rate rises and a gain when it falls.
Share of profit of associatesShare of profit of associatesGain or loss that reflects your proportional share of the net income of a company (an associate) in which you hold roughly 20–50% and have significant influence over management. It is not cash received.
One-off itemsOne-off itemsGains and losses that don't repeat every year, such as gains on asset disposals, litigation payouts and impairment losses. When projecting next year's profit or calculating P/E, it is best to filter them out.
Income tax expenseIncome tax expenseThe tax subtracted from income before income taxes. Because of tax brackets, tax credits and so on, the actual burden relative to pre-tax profit (the effective tax rate) differs by company and by year.
Earnings qualityEarnings qualityThe degree to which profit comes in from the core business, repeatedly, and as cash. If there are many one-off gains, or little cash comes in relative to profit, earnings quality is considered low.
Profit attributable to owners of the parentProfit attributable to owners of the parentThe share of consolidated net income that goes to the parent company's shareholders. It is the figure after subtracting other shareholders' share of subsidiaries (non-controlling interest), and it is used to calculate EPS.
Non-controlling interestNon-controlling interestThe part of equity in a subsidiary that is not attributable to the parent (K-IFRS No. 1110). It is shown separately in consolidated equity and consolidated net income.
Operating profitOperating profitProfit from the core business: revenue minus cost of sales and selling, general and administrative expenses.
Put what you learned to use right away
Economics Lesson 25 · Who benefits from a weak won?→Financial Statements Lesson 11 · Consolidated vs separate financial statements→This is educational material and not investment solicitation. There is no guarantee that past relationships will repeat in the future.