Case Interview Guide: Master the Case Interview at McKinsey, BCG & Bain
Case interviews are THE primary tool for consulting firms to test candidates. They are not only used by the MBB firms (McKinsey, BCG & Bain) but also by the Big 4 (Deloitte, EY, PwC, KPMG) and Boutiques (LEK, Olivery Wyman, Accenture, etc.). Below you'll learn:
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What case interviews are
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Why firms are using case interviews
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How to ace case interviews
This is a short version of our full case interview course on Udemy which we explain below.
What is a case interview and why is it so important
The consulting industry, especially at the best firms, has a highly competitive selection process. In this process, case interviews are THE primary tool to assess candidates. The idea is to check whether a candidate has the potential to become a great consultant. The case interview allows firms to test a variety of skills that are important on the job. Case interviews — in combination with other elements of the consulting hiring process such as the personal fit interview — have turned out to be the best predictors for future job performance. That’s why the concept of case interviews hasn’t changed in decades, and won’t change anytime soon.
A case interview can go into infinite directions but its typically a business or organizational matter. You’re helping a corporation or a government solve a certain problem or answer a specific question. For example:
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The CEO of a retailer is thinking about launching a new product category and you’re asked whether this is a good idea
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A bank is losing customers, and you need to help turn the situation around
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A steel producer needs to reduce costs and you’re asked to make suggestions
In principle, it’s a simplified version of a real consulting project. A real engagement may take 10 weeks of full-time work by a team of 3 or more consultants — where a junior consultant would only be responsible for a single workstream. The case interview is a gamified version of this — with the goal that you solve it all by yourself in typically less than 30 minutes. It's mutually understood that you, together with the interviewer, act out the scenario as if it was real.
Case interviews don't just exist in consulting. Hiring for strategy roles in corporates, or for private equity jobs increasingly involve case interviews. That's because over the years, many ex-consultants have been moving to these firms and with them, their practices. There's increased awareness that solving case interviews is something that also sharpens the business mind — which is why we may see even more case interviews at non-consulting firms in the future.
The 7 skills and traits you need to succeed as a consultant
Consultants are brought in by top organizations to tackle their most pressing problems. To help these organizations, consulting firms bring in high-performing teams composed of excellent individuals. Logically, a consulting firm is only as strong as its people. But what makes a strong consultant? This is an important question as the entire hiring and interview process is designed to identify outstanding future consultants.
Day to day, consultants rely on a specific set of skills and personal traits to make sense of complex problems, work effectively with others, and deliver impact for clients. There is no single “perfect” consultant profile, and many qualities can matter depending on the role or firm. That said, certain capabilities show up again and again among high-performing consultants. Below, we outline seven skills and traits that are typically critical for succeeding in the job.
Structured thinking
Consultants face messy, ambiguous problems with incomplete information. Structured thinking allows them to break complex questions into clear, logical components, ensuring analyses are focused, comprehensive, and decision-relevant rather than scattered.
Quantitative skills
Much of consulting involves sizing markets, evaluating financial impacts, and comparing strategic options using numbers. Strong quantitative skills enable consultants to test assumptions quickly, spot inconsistencies, and support recommendations with credible evidence.
Data interpretation
Consultants are often confronted with large amounts of unfamiliar information, from industry reports to complex charts and dashboards. Strong data interpretation skills help them quickly understand new industry concepts, identify what truly matters, and focus attention on the insights that are relevant for the decision at hand rather than getting lost in data.
Business judgement
Not every decision can be solved by a model or spreadsheet. Business judgement helps consultants weigh trade-offs, understand real-world constraints, and recommend solutions that are not only analytically sound but also practical and implementable.
Creativity
Clients hire consultants to see what they cannot. Creativity allows consultants to generate novel strategies, reframe problems, and design solutions that go beyond best practices when standard approaches fall short.
Communication skills
Even the best analysis is useless if it is not understood. Consultants must communicate complex ideas clearly and concisely—often to senior executives—through structured storytelling, compelling slides, and confident verbal delivery.
Likability
Consulting is a people business built on trust and collaboration. Being likable helps consultants build client relationships, work effectively in teams, and influence stakeholders to support recommendations. Being smart is great, but much more effective if you're also likable.
How case interviews test these 7 skills and traits and what makes a good performance
Case interviews are designed to simulate the core challenges consultants face on the job: ambiguous problems, limited time, unfamiliar industries, and the need to communicate clearly under pressure. Rather than testing knowledge, they are meant to reveal how candidates think, analyze, and interact. Each part of a case interview—structuring the problem, analyzing data, drawing conclusions, and discussing recommendations—maps closely to the skills and traits required in real consulting work. Below, we explain how each of the seven traits typically shows up in a case interview and what interviewers look for in strong candidates.
Structured thinking
In a case interview, structured thinking shows up immediately when a candidate breaks down the problem and proposes a clear approach. A good performance involves laying out a logical, MECE structure, explaining how different elements relate to the core question, and using that structure consistently throughout the case. Interviewers look for candidates who can guide the discussion coherently rather than jumping randomly between ideas.
Quantitative skills
Quantitative skills are tested through market sizing, profitability calculations, and numerical comparisons. Strong candidates perform calculations accurately, make reasonable assumptions, and sanity-check their results. Just as importantly, they explain their math clearly and use numbers to support conclusions, rather than treating calculations as isolated exercises. Mental math and sensible estimations are a core part of the job in fast-paced problem-solving sessions.
Data interpretation
Case interviews often include charts, tables, or exhibits from unfamiliar industries. Good performance means quickly understanding what the data shows, identifying the most relevant insights, and linking them back to the core question. Interviewers are less interested in whether candidates mention every number and more in whether they focus on what actually matters and avoid getting distracted by irrelevant details.
Business judgement
Business judgement appears when candidates interpret results and make decisions based on imperfect information. Strong candidates recognize trade-offs, consider feasibility and risks, and avoid overly theoretical answers. They demonstrate an intuitive sense of what would make sense for a real company, rather than blindly following a framework or calculation.
Creativity
Creativity is tested when standard approaches do not fully explain the problem or when interviewers ask for ideas beyond the obvious. A good performance includes generating thoughtful, relevant hypotheses or solutions that show original thinking, while still being grounded in business logic. Interviewers value candidates who can think beyond textbook answers without becoming unrealistic.
Communication skills
Communication is assessed throughout the entire interview. Strong candidates articulate their thoughts clearly, structure their answers, and adjust their level of detail based on the situation. They summarize findings concisely, make clear recommendations, and engage in a natural, professional dialogue rather than delivering rehearsed monologues.
Likability
Finally, likability shows up in how candidates interact with the interviewer. Good performance includes being engaged, confident without being arrogant, receptive to feedback, and pleasant to work with. Since consulting is a team-based, client-facing job, interviewers ask themselves whether they would enjoy working long hours with the candidate—and whether clients would trust them. You don't want to appear tense or anxious. Ideally, it feels like you're having fun and you're engaging the interviewer.
How a case interview is typically structured
The case is not the only thing you're doing in a consulting interview. The case is embedded within a consulting interview, which can consist of many potential elements. Typically it's a combination of the following:
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Introduction and small talk
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Interviewer questions about personal story and motivation
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Case interview
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Candidate questions for the interviewer
The weighting and order of those parts depends on the firm, but the case interview will always play a major role. We'll discuss the other elements of a consulting interview separately. The case itself also follows a certain structure, which typically looks as follows:
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Case briefing: The interviewer introduces the situation and outlines the problem you’re solving in the case
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Structuring: You can take some time to structure the approach. In an interviewer-led format, you can take some more time, to develop a comprehensive and very detailed structure. In an interviewee-led format, you'll take less time and develop more of a barebones version of an issue tree
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Progressing through the case: You will be presented with information and with questions by the interviewer and have to solve them. In an interviewee-led format, you have more leeway in what to do when, but ultimately the interviewer will steer you in a direction. The interviewer doesn’t have an answer or an exhibit for all possible questions, so of course there will be guidance. In an interviewer-led format, this guidance is stronger. The interviewer may ask very precise questions and provide you with a concrete exhibit
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Closing with a recommendation: After having exhausted all sensible branches of an issue tree, or simply when the interviewer says so, you're asked to give a recommendation to the client. Again you can take some time to go over the case and develop a final recommendation. This is usually complemented by supporting arguments, and maybe even some caveats, or next steps that the client should consider
The difference between interviewer-led and interviewee-led case interviews
The distinction between interviewer-led and interviewee-led describes the way the interview is conducted.
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Interviewee-led: In the interviewee-led format (also known as candidate-led format), the candidate needs to drive the case forward, while the interviewer takes a more passive approach. The candidate needs to make a plan of action, request information and perform analyses. The interviewer assists by giving out information and steering the candidate lightly
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Interviewer-led: In an interviewer-led case interview, the interviewer steers more strongly, and typically gives the candidate concrete tasks to perform
Overall, the differences between formats should not be overemphasized. In an interviewee-led format, the interviewer will still provide guidance. The case must come to a conclusion and the interviewer wants you to get on the right track eventually – so it has elements of an interviewer-led format. Moreover, the interviewer can't allow you to explore any direction of the case as she only has exhibits and information on a limited number of branches in the issue tree. On the other hand, an interviewer-led case doesn’t mean you can sit back and wait for orders by the interviewer. You’re asked to be proactive, make a plan, suggest next steps, and drive the case. At least that’s what good candidates do. So there’s less of a difference than you think, and if you’re great at cases, you’ll succeed in any format – the skillset you need is the same.
McKinsey is the one company that insists on an interviewer-led format and uses exclusively this style. Other firms are less stringent and typically lean more towards an interviewee-led style like BCG and Bain & Company. But again, there’s a big overlap.
Full case interview vs. brain teasers
Brainteaser test a narrower skillset, typically only one or two aspects of a full case interview. This could be your creativity, your conceptual problem solving, or your quantitative abilities. They aren’t used by the big strategy consulting firms, but can be found at other firms. Even non-consulting firms, like corporates are known to give brain teasers.
If you know that a firm is using them and what skills they’re looking for, you can try and specifically prepare for them. Otherwise it’s a safer bet to become good at case interviews in general, as you’ll master the whole palette of required skills.
Classic examples for a brain teasers would be:
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How many golf balls can you fit into an airplane?
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It can also be closely related to a market sizing question, for example: How many pencils are sold annually in the US?
The cornerstone of solving brain teasers is being structured and following a logical step-by-step approach. In this way, brain teasers are very similar to case interviews. Just break down the brain teaser into smaller, more manageable components and start from there.
Facts and metrics to know for case interviews
While case interviews are not designed to test factual knowledge or industry expertise, they do assess whether a candidate has a basic grasp of business reality. Interviewers expect candidates to use reasonable assumptions, be aware of common benchmarks, and avoid statements that are clearly implausible. This baseline knowledge allows for a sensible, professional discussion and signals that a candidate could credibly be placed in front of a client. Strong performance therefore combines clear thinking with ideas that are grounded in real-world constraints rather than purely theoretical reasoning.
For brain teasers as well as for case interviews, it can be quite useful to know certain facts. For example, you want to know key leaders of the largest countries, and some basic facts about what's going on in the world. It's also good to know some key numbers about countries and geographies. For example, it is good to know that the US have a population of around 300 million. This would already help you in the market sizing example stated in the list above. No one expects you to know the population of any country in the world. Just memorize the key markets and the specific market of the office you are applying to. Here are some key population figures that are useful:
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Global: 8 billion
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USA: 300 million
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Europe: 750 million
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EU: 450 million
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China: 1.4 billion
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India: 1.4 billion
Notice how these figures are all rounded, often quite generously. But that's perfectly fine, we just want to get a rough figure, an order or magnitude if you will. Aside from population figures, there are some facts that are quite handy to know. For example it is useful to roughly know the relationship between the following metrics (the numbers are again rounded for simplicity):
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1 mile is 1.6 kilometers
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1 inch is 2.5 centimeters
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1 gallon is 3.8 liters
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1 foot is 30 centimeters
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1 pound is 0.5 kilogram
These are basically things that an open-minded, educated individual should know anyways. If you don't know, however, ask the interviewer. Don't run in a completely wrong direction in your case because you had no clue about something and were too afraid to ask. Better ask a dumb question than completely mess up your case. For the more obscure facts (e.g., how many pounds/kg one stone is (UK weight measurement)), it is anyway fine to ask the interviewer. No one expects you to know such things.
If you've gained some experience abroad (i.e., to understand the relationship between the metric and imperial system) and walk through life with two open eyes, you are probably familiar with the most important metrics that could come along in a case interview. Don't overemphasize memorizing facts and figures. Your time is much better spent on preparing for the case interview and working on personal fit. We have never seen the need to know the GDP of one specific country or region at case interviews at MBB firms. If you are applying for specific roles at boutique consulting firms that focus on economics this advice is obviously not applicable.
Alternative settings and interview types
There are case interview variations where you’re not 1:1 with the interviewer, but in a different setting. All of these variations are similar, and the foundation of your preparation should be regular case interviews. They typically test an additional aspect of your skillset that the particular company deems important.
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Group case interviews: You’re solving the case together with other people, similar to an assessment center. The idea is to test how well you interact with a group of people. Of course you need to make sure that you’re making valuable contributions. Don’t just say something to have a large share of voice, but make your contributions count. Most crucially though, you need to involve other people. Listen to their ideas and don’t be shy to praise team members. Actively involve other team members in the problem solving approach. Don’t shoot down ideas or interrupt people. A consulting project is never a competition among team members. It’s about helping each other, and making each other shine.
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Written case interviews: In a written case interview, you’re often given large amounts of data, sometimes dozens of slides. Then you have an hour or two to review the information, make the necessary analyses, and create slides to present your findings. Since the end product of a consulting engagement is basically always a slide deck, written communication in PowerPoint format is extremely important, which is tested in this type of interview. If you anticipate this type of interview, make sure that your PowerPoint skills are solid and you can quickly create a presentation with basic charts and graphs. Check out presentations of consulting firms which you can find online.
Different aspects of all these variations may be combined, and include a written portion, a discussion in a group, or a presentation in front of interviewers. The better you understand the job of a management consultant, the better you know what the interviewers are looking for. So try and learn as much as you can about the consulting industry. And of course, make sure that your case interview fundamentals are strong, since they will serve you in all situations.
General good habits in case interviews
Regardless of the firm, the format, or the case, there are a few habits that you can employ, which will always serve you well.
Listen carefully
Pay close attention to the problem description and any additional information provided. Understanding exactly what the interviewer is asking prevents wasted effort and ensures your approach addresses the right question.
Take notes
Capture key numbers, facts, and insights as the case unfolds. Good notes help you organize your thoughts, avoid forgetting details, and serve as a reference when analyzing complex information.
Ask clarifying questions
Don’t hesitate to ask questions to remove ambiguity or confirm assumptions. This shows engagement, ensures you fully understand the case, and helps you structure your approach effectively.
Take your time
Think before you respond, especially when structuring the problem or performing calculations. Pausing to organize your thoughts leads to clearer, more accurate reasoning rather than rushing into errors.
Communicate with the interviewer
Share your thought process out loud and involve the interviewer in your reasoning. Continuous communication keeps the discussion aligned and demonstrates structured, confident thinking.
Synthesize
Regularly summarize your findings and key insights throughout the case. Clear synthesis shows you can distill complex information into actionable conclusions that drive decision-making.
Drive the case with intent
Take ownership of the problem and guide the analysis toward a solution. Strong candidates actively shape the direction of the case rather than waiting passively for prompts.
