Types of Case Interviews: 6 Must Knows

There are multiple types of case interviews you must pass before landing a coveted job offer. That’s right – writing the perfect resume and preparing for the fit interview are just the beginning of your work! Just as there’s always a dragon to slay before rescuing the princess, there’s a case interview process to master before landing the job. To effectively prepare for the case interview, you must understand the types of case interviews you will see. In this guide, we break down 6 popular types of case interviews and how to navigate each one.

Before we get into the specific types of case interviews, let’s start with a quick overview. You can find a great overview and case prep guide here.

Consulting firms rely heavily on case interviews to find the right candidate and therefore, you should practice strategically, start practicing early (at least 2-3 months prior to the interview), and then keep practicing often.

Why? The case interview is where you demonstrate that you have the skills to do the job. 

Case interviews offer an in-depth view of how you think, function under pressure, solve problems, and marry big-picture context with attention to detail.

In addition, they are excellent test scenarios for your communication ability. A winning candidate does more than spout business knowledge – you are tested on how you build and communicate a clear framework, break down problems into small pieces, develop real-world options, and recommend actionable solutions with executive presence.

Two case interview styles exist: Interviewer-led (used at McKinsey) and interviewee-led (used almost everywhere else). When we coach candidates 1:1, we will focus on the differences in great detail – but that’s not the point of this article. Within both case styles, you will encounter a variety of case interview types.

Today, we’re focusing on 6 of the most popular types of consulting case interviews. You will see any one of these 6 variations (and probably multiple ones) throughout your case interview process. Therefore, it is important to be familiar with each one of these interview types.

It’s important to note, that in all likelihood, your case interview won’t be a singular type, but a mix of multiple from those below. That said, you still need to have a solid understanding of each of them, and be able to leverage different parts of them to create your own framework to meet the business problem presented to you.

Types of Case Interviews:

1. Market Sizing Framework

Market sizing questions are fairly straightforward, solved in 6-10 minutes with 6-9 steps (including 1+ levels of segmentation). You are calculating the annual sales of a good or service, although the interviewer could alternatively ask you to calculate total units sold. Market sizing questions are common in Big 4 interviews, as one piece of longer MBB cases, and at the undergraduate level across firms.

Sample market sizing questions include:

• • What is the size of the U.K. market (£) for helium balloons?
  • Size the market for housecleaning services in New York City.
  • How many hamburgers are consumed in the U.S. in one year?

When part of a longer case, you are using the size of the market as a baseline to answer strategic questions like:

1. 1. How many of X exist in the market?
   2. How fast is the market for X growing?
   3. What is the $$ opportunity if a client introduces X into the market?

In many market sizing cases, the interviewer has no clue of the exact solution – nor does she care. When this happens, the market sizing prompt is an estimation question. In an estimation problem, the emphasis is more on how you arrived at your conclusion (Did you go off on a tangent? Did you state your assumptions? Could you defend your assumptions? Could you gut check your answer?) rather than the conclusion itself.

Also, in market sizing questions, be prepared for adjustments at the end of the question – “What if the % of the population used was this? What is your most sensitive assumption?” Because you are basically preparing a manual spreadsheet (a mini-financial model) on the fly, be prepared to adjust your inputs – just like you would on a real-life consulting project.

2. Profitability Framework

Profitability is the ultimate business metric, and profitability cases can address a business in any industry. This case type names a company and gives some detailed history and factual data, and poses one of three questions: 

• • What should Company X do about revenues (prices x volumes)?
  • What should Company Y do about costs (fixed costs + variable costs)?
  • What should Company Z do about overall profits (including both sides of the profit equation using metrics such as profit/unit or profit/channel)?

In our worldview, there are 4 types of profitability questions:

1. 1. Declining profitability
   2. Profitability – revenue-focused
   3. Profitability – cost-focused
   4. Profitability – scenarios

In the first type, profitability questions can cover why a company might be losing profits or what a company should do to increase profits creatively. Your job is to set up a framework to help them find the source of the issue.

Revenue- or cost-focused profit questions aren’t necessarily posed as profit questions (the word profit isn’t used in the set-up). For example, maybe a company is integrating a new software infrastructure and they want to know if it’s a “good idea”. The focus is on quantifying the benefits of new business infrastructure solutions – benefits that translate to increased sales or reduced costs.

Also, revenue and cost questions may be focused on non-financial decision making – for example, “X is deciding whether or not to run for office. Should they or shouldn’t they?” Meaning, they are not referring to financial outcomes, but are still quantifiable – your job is to think about the issue with a 360-degree view and develop a well-structured pro (“revenues”) and con (“costs”) list of questions.

Lastly, you might encounter a scenario question. You will be given 2 options and will need to compare the profitability of one against the other. An example of this might be comparing the use of the U.S. Post Office for mailing needs versus UPS. Or maybe the company is trying 2 different types of packaging for a product; one is 3 oz. and the other is 8 oz. Which packaging would you recommend and why?

3. Market Study Framework

Market study questions come in 3 main forms:

1. 1. Market Entry
   2. Revenue Growth
   3. Market Share

The first point in this case interview framework, market entry, addresses a scenario where a company is interested in entering a new market. You are really answering another question – how much money will they make, will they be profitable entering that market, or how should they enter that market?

In the second scenario, a company is trying to grow their revenues. Your job would be to ultimately determine how they could obtain this goal. If you look at it through the lens of profitability, would it be by increasing prices or volumes? (Market study would be the second level of analysis). If you look at it through the market study lens, you look at market factors (competitors, customers, supply/demand, etc.) that would affect growth plans – and profitability would be the second level of analysis. In either case, you will want to make a clear recommendation on how to grow revenues and identify identify warning signs that might hinder this company from achieving this goal.

Another type of market study question would address a company declining in market share. In this scenario, you need to focus on overall company growth/decline and how it has been affected by competitors, market changes, and customer loss. You are looking for a way to grow in context to the current market and competition.

4. Merger & Acquisition Cases Framework

M&A cases are the mac-daddy of all consulting cases because they include market sizing, profitability, and market study components – with a fair share of case math thrown in. The cases will either be about whether Company A should merge with Company B or if Company Y should purchase Company Z.

These case prompts often start with a limited amount of factual data relating to both the target business and client company. When asking 1-3 clarifying questions and creating your framework, focus 80% on the target and only 20% on the parent/acquirer/client.

There are 2 key types of Merger and Acquisition purchasers – financial and strategic acquirers. Understanding the motivations of both short-term financial purchasers and long-term strategic acquirers will help you identify how best to evaluate the target. Remember, however, the goal for both types of acquirers is…as always…increased profitability.

5. Brain Teasers

Brain teasers are most commonly logic puzzles or riddles. They are meant to test both your analytical and creative thinking process.

Here are some sample brain teaser questions:

• • How many golf balls can fit in a football stadium?
  • How many miles of road are there in the United States?

In their purest form, brain teasers are uncommon in management consulting interviews, but we include them for 2 reasons. One, it’s good to be prepared for them in case you have an interviewer who decides to throw them in. Two, you solve them the same way you solve a market sizing question (see above) – by breaking down the solution into its component parts. Always state your assumptions, back them up with rationale, and talk the interviewer through your entire thought process. 

6. Consulting Math

Consulting is a data-based industry – and where there are no facts, there are well-developed estimates. During the case interview, you will not have the privilege of using a calculator. You will face math ranging from simple addition/multiplication to more advanced concepts like calculating ROI or other business formulas.

These are not usually stand-alone case interview questions for MBB (although they could be in a time-pressured partner interview), but they are great practice for Problem Solving Tests (PST’s), digital assessments, and as components for longer strategic case interviews. Here’s a sample question:

• • About 225 of Smith Investments’ ~20,000 employees have the title of partner. What percentage of all Smith’s Investments employees are partners?
  • The market for lead pencils has been declining at 4% per year for the last 3 years. The original market was $24M per year. What is the market in year 3 (now)?

Unlike scientific math calculated to multiple decimal points, consulting math only expects close-to-correct rounded answers. In science or technology, a tiny margin of error can lead to major accidents. However, in business, decisions can be effectively and efficiently made based on near-perfect data/calculations. Plan to calculate to the ones place in all case math and propose rounding to your interviewer after you’ve already proven yourself in a few calculations.

In digital assessments, multiple consulting math questions like these are asked with a time limit – either in spoken form or in written form, and you usually have under 2 minutes to answer each question. In written form, they are usually multiple choice questions.

Our FREE mental math drills are a great place to begin your practice.

Conclusion

After you have a better understanding of the case types, that’s where the real work begins – developing actionable case interview frameworks for each.

In any case type, you will need to start the opening sequence by recapping the question back to the interviewer. This will help you ensure that you understand the scenario presented as well as the case objective. Make sure you include all the factual details given. Your recap should take 30-60 seconds and reflect your understanding of what the company does, what the company is trying to decide, and how they currently make money. Be confident – it’s your first impression.

Then you ask the interviewer 1-3 clarifying questions to help repeat information you’ve missed, confirm your understanding of the business, or get greater clarity on the case objective.

When developing your case interview framework (2 minutes in silence!), remember to set it up like you would set up the workstreams on the project if you were leading it. You are not being asked to conduct a hypothetical analysis, and you’re not brainstorming solutions. What are the key data points you need and what key questions do you want answered that will help lead you to solving the case objective?

Okay, now that we’ve walked through these 6 popular case interview types, it’s time to get cracking! Work with us through our Black Belt interview prep program. You’ll work 1:1 with a MBB coach to fine-tune your case interview skills and land your dream consulting offer!

Want more reading? Check out more articles around this topic:

• Market sizing case interview
• Market sizing question examples
• Profitability Case Interview Framework
• Case Interview Questions by Type
• Case Interview: Complete Prep Guide