Lesson 2 of 12
Profitability case interview: framework and worked example
Profitability cases ask one question: why is this company making less money, and what should it do about it? This lesson gives you a framework you can adapt to any industry, walks through a full example with real math, and covers the mistakes that cost candidates offers.
Part 1 of 9
What is a profitability case?
A profitability case asks you to explain why a company's profits have changed, almost always downward, and to recommend how to fix it. You might hear it framed as falling profits, shrinking margins, a division that is losing money, or a target the CEO wants to hit.
It is one of the most common case types in consulting interviews, and it shows up inside other cases too. Market entry, M&A, and new product cases usually include a step where you work out whether something will make money, so the thinking you build here carries over to almost every case you will see.
The skill being tested
Anyone can say profit equals revenue minus costs. The interviewer is watching whether you can find which specific piece of the business broke, prove it with numbers, and turn that into a clear recommendation.
Part 2 of 9
How to spot a profitability case
Most prompts tell you directly. Listen for phrases like these:
- Profits have fallen over the last two years
- Our margins are below competitors
- The division is losing money
- How can we improve profitability?
- The CEO wants to reach a 15% operating margin
- Costs have grown faster than sales
Watch for disguised versions too. A prompt that says revenue is growing but the board is unhappy is usually a profitability case. So is a question about whether to shut down a product line: before you can answer it, you need to know how much money that line actually makes. Not sure which type a prompt is? The first lesson covers how to identify the case type.
Part 3 of 9
The profitability framework
Start with the equation, then break each side down until every branch is something you could actually measure.
- Profit
- Revenue
- PriceList price, discounts, product mix
- VolumeBy product, customer, channel, region
- Costs
- VariableMaterials, hourly labor, commissions
- FixedRent, salaries, overhead
- Revenue
External factors: why did it move?
- Market
- Competitors
- Customers
The revenue side
Revenue is price times volume. Price covers list price, discounting, and mix (selling more of the cheaper or pricier items). Volume is where most insights hide, so split it the way this business actually earns money: by product line, customer segment, channel, or region. For a retailer, that might be number of stores times revenue per store.
The cost side
Split costs into variable and fixed. Variable costs move with every unit sold, like ingredients, packaging, shipping, hourly labor, and commissions. Fixed costs stay flat as volume changes, like rent, salaried staff, and overhead. Compare each cost as a percentage of revenue, not just in dollars, so growth does not hide a real problem.
The branch most candidates forget
Is the overall market growing or shrinking? Have competitors cut prices or entered? Have customers changed what they buy or how they buy it? If every company in the industry saw profits fall 20%, your answer looks very different than if your client is the only one struggling. Asking about competitors early is one of the fastest ways to show business judgment.
Say it in the client's language
"Revenue per store times number of stores" sounds like you understand a coffee chain. "Price times quantity" sounds like you memorized a framework. Rename every branch for the business in front of you.
Want to see how this tree fits with the other core structures? The frameworks guide covers all of them side by side.
Part 4 of 9
How to solve it, step by step
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Clarify the goal
Confirm what profit means (operating profit is the usual default), how much it moved, over what period, and whether there is a specific target. Ask whether anything major changed, like new locations or an acquisition.
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Lay out your structure
Ask for a moment to think, then walk the interviewer through revenue, costs, and external factors, tailored to this business. Say which branch you want to test first and why.
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Find which side broke
Compare revenue and costs across the time period. Did revenue fall, did costs rise, or both? Convert costs to a percentage of revenue to see which ones grew faster than the business.
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Segment until you hit the root cause
Totals hide problems. Break the broken side down by product, channel, customer, or region until you can point to one or two specific drivers.
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Recommend with numbers
Lead with the answer, quantify the impact, give two or three concrete actions, and name the risks and next steps.
Part 5 of 9
Worked example: BrewHouse Coffee
Try each question on your own before you reveal the answer. Say it out loud if you can, the way you would in an interview.
Case prompt
Your client is BrewHouse, a regional coffee chain with 120 stores across the Midwest. Over the past two years, revenue has grown slightly, but operating profit has fallen by 40%. The CEO wants to know why, and what to do about it.
Question 1
How would you structure this problem?
A strong answer asks two quick clarifying questions first. Is the store count the same? Yes, 120 stores in both years. Is the 40% decline in operating profit? Yes. Then it tailors the tree to a coffee chain:
- Revenue: number of stores times revenue per store, with revenue per store split by channel (in-store versus delivery apps) and by transactions times average ticket.
- Costs: variable costs like coffee, milk, cups, hourly labor, and delivery app fees; fixed costs like rent, store managers, and corporate overhead.
- External: is coffee spending growing, have national chains or new local shops cut prices, and are customers changing how they order?
Since revenue went up while profit went down, a good candidate says they want to look at costs first, while keeping an eye on how the revenue mix changed.
Question 2
The interviewer hands you Exhibit 1. What is driving the profit decline?
Exhibit 1: BrewHouse financials ($M)
| Line item | Year 1 | Year 3 |
|---|---|---|
| Revenue | ||
| In-store sales | 90.0 | 72.0 |
| Delivery app sales | 10.0 | 32.0 |
| Total revenue | 100.0 | 104.0 |
| Costs | ||
| Food and beverage | 30.0 | 31.2 |
| Store labor | 30.0 | 31.2 |
| Rent | 15.0 | 15.0 |
| Delivery app commissions | 2.0 | 8.0 |
| Other operating costs | 11.0 | 11.4 |
| Total costs | 88.0 | 96.8 |
| Operating profit | 12.0 | 7.2 |
Store count: 120 in both years.
Revenue grew 4% while costs grew 10%, so costs are the problem. The fastest way to see which cost is to put each line as a percentage of revenue:
| Cost as % of revenue | Year 1 | Year 3 |
|---|---|---|
| Food and beverage | 30.0% | 30.0% |
| Store labor | 30.0% | 30.0% |
| Rent | 15.0% | 14.4% |
| Delivery app commissions | 2.0% | 7.7% |
| Other operating costs | 11.0% | 11.0% |
| Operating margin | 12.0% | 6.9% |
Food, labor, and other costs held steady as a share of revenue, and rent actually fell. Delivery app commissions jumped from 2% to almost 8% of revenue. That one line explains $6.0M of the $8.8M cost increase, which is more than the entire $4.8M profit decline.
Profit bridge, Year 1 to Year 3 ($M)
Now look at the revenue lines. In-store sales fell $18M while delivery sales grew $22M. Customers are not just adding delivery orders on top. Most of them are switching.
Question 3
The commission rate on delivery orders rose from 20% to 25%. Break the $6.0M commission increase into the part caused by higher delivery volume and the part caused by the higher rate.
Rate effect (rate increase on all current delivery sales): $32M x (25% - 20%) = $1.6M
Check: $4.4M + $1.6M = $6.0M
So most of the damage comes from customers moving to delivery, not from the rate hike. If the $18M in-store decline is customers switching, BrewHouse now pays 25% on sales it used to keep in full: $18M x 25% = $4.5M a year, close to the entire $4.8M profit decline.
Stating the "so what" after the math is what separates good answers from great ones. Need more practice with this kind of calculation? The math drills build speed on percentages and margins.
Question 4
The CEO walks into the room. What is your recommendation?
"BrewHouse's profit fell 40% mainly because customers moved from ordering in the store to ordering through delivery apps, where BrewHouse pays a 25% commission. Commissions alone rose $6M, more than the full $4.8M drop in profit.
I'd recommend three moves. First, launch an order-ahead pickup option in BrewHouse's own app, with loyalty rewards to win back customers who switched. Every $1M that shifts back saves $250K in commissions. Second, price delivery menu items 10 to 15% higher to pass part of the commission on to delivery customers. Third, negotiate a lower rate with the apps, possibly by consolidating onto one partner.
The main risk is losing the roughly $4M of delivery sales that are truly new, so I'd test the price increase in a few stores first. As next steps, I'd look at customer data to see who switched and pilot the pickup option in one city."
Why this works: it opens with the answer, backs it with the numbers from the case, gives specific actions with sized impact, and names a real risk with a way to test it.
Part 6 of 9
Common mistakes
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Reciting a generic framework
Interviewers hear "price times quantity" all day. It signals memorization, not thinking.
Instead: name the revenue and cost drivers for this specific business.
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Stopping at the totals
In the example, total revenue grew, which hid the shift from in-store to delivery.
Instead: segment revenue and costs before drawing conclusions.
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Comparing costs only in dollars
When a business grows, almost every cost grows in dollars too.
Instead: compare each cost as a percentage of revenue to see what grew faster than the business.
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Skipping the outside world
A profit drop that hit the whole industry calls for a different answer than one that hit only your client.
Instead: ask how competitors are performing early in the case.
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Ending with ideas instead of a recommendation
A list of ten possible fixes is not an answer.
Instead: pick two or three actions, size their impact, and name the risks.
Part 7 of 9
Variations you'll see
The same framework handles every version below. What changes is where you point it. If the question is how to grow revenue rather than fix profit, that is a growth strategy case.
- Declining profits
- The classic form, like the BrewHouse example. Find what broke and fix it.
- Margin gap versus competitors
- "Our margins are five points below our peers." Compare the client's prices and costs line by line against competitors to find where the gap comes from.
- Hitting a profit target
- "Get from an 8% margin to 12% in three years." Size the gap in dollars first, then build a set of levers that add up to it.
- Unprofitable product or division
- Decide whether to fix, reprice, or exit. Watch for fixed costs that would stay behind even if the unit shut down.
- Break-even questions
- "How many units do we need to sell to cover our costs?" Break-even volume equals fixed costs divided by (price minus variable cost per unit).
Part 8 of 9
Practice what you learned
Reading a framework is not the same as using it under time pressure. Put this lesson to work:
Try a full case
More ways to practice
Part 9 of 9
Frequently asked questions
What is the profitability framework in a case interview?
It starts with profit equals revenue minus costs. Revenue splits into price and volume, costs split into variable and fixed, and a third branch covers external factors like the market, competitors, and customers. Strong candidates rename each branch to fit the client's business.
How do you structure a profitability case?
Clarify the goal and timeframe, lay out a tailored revenue, cost, and external structure, find which side of the equation changed, segment that side until you reach the root cause, then recommend two or three actions with numbers and risks.
Should I start with revenue or costs?
Start with whichever the data points to. If revenue grew while profit fell, costs are the likely culprit. If you have no data yet, ask for the revenue and cost trend over time before committing to a branch.
What math comes up in profitability cases?
Expect percentage changes, margins, costs as a percentage of revenue, per-unit economics, and break-even calculations. Mental math speed matters because interviewers usually expect you to calculate without a calculator.
How is a profitability case different from a market entry case?
A profitability case diagnoses an existing business that is underperforming. A market entry case asks whether a company should enter a new market, which includes a profitability estimate along with market attractiveness, competition, and how to enter.
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