You are contacted for an interview at a top consulting firm – or more ideally for a consulting candidate, you are in the months-long preparation stage, looking for a way to nail every possible question the interviewer might throw at you.
Your best solution is to follow the true consulting spirit – break the questions down into a few manageable types, and one-by-one learn how to handle all of them. Using my experience at McKinsey, and in coaching countless promising candidates, I’ll lay down a framework and guide you to deliver the best answers that land you a consulting job.
What are consulting interviews?
When most people say “consulting interview”, it’s usually one of these two kinds:
- One is the “networking interview”, where you establish contact and relationship with working or former consultants, trying to get a foot in the door. Networking is usually done through formal events or informal connections, and it’s the first step to get into consulting firms.
- The other is the “consulting job interview” – consists of a fit interview and a case interview. Each of these parts also consists of predictable question types, which I’ve already broken down and discussed extensively in their corresponding articles (see below).
This article is mostly written for the latter, but even in the former case the consultant may still ask you similar questions (to make sure he/she is talking to a promising candidate). With the key definitions now clarified, let’s dive in.
Types of questions in consulting interviews
In consulting interviews, there are 4 common types of questions:
- Ice-breaker questions (with 3 subtypes)
- Fit/behavioral interview questions (with 3 subtypes)
- Case interview questions (with 8 subtypes)
- End-of-interview questions (that you ask the interviewer)
For each type, we’ll have an example and instructions for answers. Keep in mind that these cannot cover all possible questions in consulting interviews – be it the job interview or networking interview. Some of these categories are quite generic (such as the fit questions), and senior/experienced consultants are more likely to ask unpredictable questions.
What interviewers look for in consulting interviews
You must understand what interviewers look for to craft the best answers for each question. Different firms and different consultants have different wordings, but here’s how I summarize it:
The core attributes
- Problem-solving skills: I’m talking about the analytical aspect of problem-solving – the whole consulting industry exists on the basis that consultants can break down business problems better than anyone else.
- Leadership ability: Getting a bunch of experienced people (your clients) to do something they don’t want to is never easy; additionally, consultants usually work in teams. Keep in mind, “leadership” is about influencing people, not about getting nominated as the class monitor.
- Achieving mentality: The problems are always big and difficult, while deadlines are tight; don’t even think about work-life balance here, you have to go all-out. People unwilling to work that hard are never kicked out of the industry, because they never get in!
The good-to-haves (but not always required)
- Business background: This isn’t a requirement for prospective consultants; however, business knowledge is essential to excellent performance in case interviews. Luckily, it’s something you can learn, and most concepts used in consulting interviews are on basic to intermediate levels.
- Technical skills: These skills are required for specialist positions, such as at McKinsey Digital. Precisely what kind of expertise or technical knowledge is tested will be informed to you by McKinsey, so don’t worry too much.
Every word you say must somehow reflect at least one of the three core attributes, while the whole interview must showcase that you have all of them. Business background and technical prowess give you “bonus points”, so show them whenever possible.
Question 1 – Good morning, how are you doing?
Yes, the classic ice-breaker question. It shouldn’t be a difficult challenge – I mean this is just basic social interaction. Yet I’ve seen countless interviewees messing this one up with a dry and nervous “I’m fine” (both in consulting interviews and other interviews I’ve conducted after I left McKinsey). The biggest problem here is anxiety – when under stress, even the most basic actions may seem challenging.
Ideally, your answer should be detailed, positive, and reciprocal (the last one means you should ask them back). This is how you make a good first impression and keep the conversation going; on the other hand, just saying “I’m fine” is a conversation-stopper. Some interviewers ask this question just as courtesy, but other experienced interviewers can use this to assess your client interaction – which is of foremost importance in consulting.
This is how you answer it:
“I’ve had a really nice breakfast just outside this office so today has been a great start. What about you – how are you today?”
Question 2 – What do you think about the office?
Answers for this question should follow the same rules as with the previous one – except you should be observant. And be sincere, blatant flattering doesn’t make good impressions.
Preparation is simple – pay attention to your surroundings when you enter their office. Consulting firms appreciate people who can notice the small but important details.
Here’s an example answer:
“I like the way this building uses glass to maximize natural lighting. It must really be easing on the eyes, I prefer that to artificial lights. Is it the same for you?”
Question 3 – Tell me about yourself/Walk me through your resume
Here’s when things get more serious – and slowly transition to the fit interview part.
The most common mistake for candidates in consulting and in general, is to ramble without any focus. Interviewers want answers relevant to the job and the firm in particular, not a 10-minute recital of everything you’ve done since high school.
And because this is a consulting interview, you should organize your answer clearly and make it MECE – use a Present-Past-Future structure can help a great deal. Focus on only 2-3 key points in your resume, and try to have a “so what” strongly connecting your profile with the firm – in this case, showing that you have the 3 necessary attributes, and that consulting aligns well with your future plans.
“Surely. To introduce myself, I’d like to talk about 3 things: 1. my current job, 2. my past working experiences, and 3. my plans for the future. Is that okay for you? [the interviewer nods]
Thank you. So for my current job, I am […] In the past, I also worked as […] As for my future career, I plan to […] which leads me to apply for the position of Business Analyst at your firm. As being a good analyst requires […] I believe my experience in […] would make a great addition to the projects.”
Read the full guide here: Consulting Fit Interview/ McKinsey PEI
Question 4 – Why consulting/Why our firm?
You will see this question in 3 out of 4 consulting interviews.
Interviewers ask these questions to help them rule out lazy candidates who can’t bother to research about a firm/a job, or people who jump ship at the slightest chance.
As such, your reasons must be unique, specific, authentic, and appropriate. Additionally, it must be structured – and preferably MECE.
Unique means the answer is unique to your plans and preferences, while specific means it’s only applicable to the firm you’re interviewing for; it should be factual (or at least you have “sources” to back it up – for instance, you asked a few consultants and they said the same thing), not something you’ve just made up; and lastly, not every reason is suitable for an interview – for example everyone wants high salary and good exit options, but don’t suggest you are “in for the money then bail out in 2 years”.
Then how do you structure your reasons? A simple trick is to number them. Like this:
“I decided to apply to join McKinsey because of three reasons: 1. […] 2. […] 3. […]”
Question 5 – Tell me about that time you [insert extraordinary feat]
This is a behavioral question, and it appears in virtually every consulting fit interview, and it sits at the core of the McKinsey PEI. Interviewers use your answer to assess the qualities, motivations and personality traits needed in the firm, and therefore, this question gets the highest priority in fit interview preparation.
The key to nailing behavioral questions lies in powerful and convincing story-telling, which consists of three steps:
- Lay down the content base – Select 3-5 “extraordinary” stories in your personal and professional life, then gather all related details.
- Form the story plot – For each story, trim away the unimportant and technical details; enhance the rest to reflect the qualities most important to consulting (leadership, achieving, and problem-solving).
- Refine your style – Practice telling those stories until you see people listening to you attentively; the point is to create a charming, unique and natural style for yourself – good storytellers always have their styles.
Everyone has their own stories, and considering the time and space constraints of this article I won’t post a detailed story here. However, in my Case Interview End-to-End Secrets Program, I discussed in great length about how to craft a powerful PEI story, using my own example.
Question 6 – What do you do in your free time?
Unlike the previous behavioral question, “personality questions” (I call them as such because usually interviewers ask these to explore who you are as a person) are nowhere near as tricky. Just be yourself.
With that said, this is an opportunity for you to show that you’re an interesting person (in a positive way), and that you demonstrate consulting attributes (achieving/leadership/problem-solving) in everything you do. If I was in this situation, I would not hesitate to start bragging about my achievements in paragliding:
“I love paragliding. It’s not just the joys of flying that gets me – but also the research and strategy involved before and during every flight. In fact, I believe analytics is one of my strengths as a pilot – which helped me win a SEA championship back in 2019.”
Beware of follow-up questions
Whether you’re introducing yourself, explaining your application or showing your extraordinary achievements, the interviewer will always have follow-up questions to determine how much BS you are using. Consulting interviewers are highly skeptical and fact-based.
That means you have to know your stories/resume inside-out, and outside-in. Predict the possible weak points and the likely follow-up questions and prepare your answers in advance; don’t freeze and panic if you’re met with an unexpected question – real management consultants must always remain calm and solution-driven in front of their clients.
The following questions and answers are streamlined for demonstration purposes; real case interviews have much smoother transitions and require more complex issue trees/calculations.
Question 7 – What factors would you consider to address our client’s problem?
This is what I call “framework/issue tree question”. To answer them effectively, you need to understand the consulting problem-solving fundamentals, and master a few important case interview frameworks, and thoroughly grasp the MECE principle.
For this question I’ll use a hypothetical case of a fictional firm called “Eagle Aviation”. Eagle Aviation produces manned airplanes for military and civilian use. Although the firm remains a major player in the market, it has seen some serious decline in revenue in the last 5 years, leading to profit loss, so they called in your team to address the problem.
Here’s one way to answer the given question:
“To address the root cause of Eagle Aviation’s declining revenue, I would break the revenue down according to their market segments and use data to pinpoint where the problem is coming from. For Eagle Aviation, there are two main segments: ‘military’, and ‘civilian’. The military often buys two types of airplanes – “combat”, such as fighters, and “non-combat”, such as cargo planes. On the civilian side, there are also two types: “commercial”, like the large airliners, and “non-commercial”.
<literally draws out an issue tree and points to it as you speak>
Question 8 – How many tennis balls can you stuff inside an airplane?
Read the full guide here: Market-Sizing & Guesstimate Questions
This is a “guesstimate question” – where you make an educated estimate of a vague and obscure number. Its purpose is to see if you have a structured approach to solving problems; accuracy is good, but not important.
To make such an estimate, follow these four steps:
- Step 1: Clarify all unclear terms in the question
- Step 2: Break the number down into 3-5 small, easy-to-estimate pieces
- Step 3: Estimate each piece using math and background knowledge
- Step 4: Consolidate the pieces to arrive at the final result
Here’s how I’ll solve the problem:
“Thank you for the interesting question. Before I can answer it, I would clarify three points to make sure that we are on the same page:
- The tennis ball is of the normal size
- The airplane is a small jetliner like the Boeing 787
- “Stuff inside the airplane” means inside the main tubular frame or the fuselage – spaces in other parts such as the wings do not count, and the frame is completely empty, without any equipment or furniture. Does that sound good to you?”
<the interviewer agrees>
“It’s great to see that we can agree on the important details. To answer your question, I would need to break it down into small components for easier estimations, so can I have a minute?”
<the interviewer agrees so I use the timeout to draw the issue tree>
“To know how many tennis balls we can stuff inside an airplane, we would need to estimate the volume of the tennis ball, and the volume of the fuselage.
- The average tennis ball is about 130cm3 or 0.00013m3
- The typical small jetliner will have a tube-shaped fuselage 200m in length and 3m in radius, which makes about 5,500m3 of volume.
Combining these figures, we can come to the conclusion that we can stuff roughly 42,000,000 tennis balls in a typical small jetliner."
Notice how I always use round numbers and try to structure my answer as much as possible during this example – the former is to help my brain process calculations faster, while the latter is to help the interviewer follow my answer and make a good impression that I have a “structured” mindset. Also remember to perform your calculations quickly and mentally (you don’t want to bore the interviewer to death while you do the math)
Question 9 – How much Earl Grey is drunk in Britain each year?
Read the full guide here: Market-Sizing & Guesstimate Questions
This is a “market-sizing question”, and it’s a subtype of a guesstimate question. The approach is the same – structure gets the priority, not accuracy – except here you need a bit more business intuition. Again, you use the same four steps as with guesstimate questions: (1) clarify, (2) break the problem down, (3) estimate each piece, and (4) consolidate.
Here’s how I estimate the number:
Thank you for this very interesting question.
Before diving into the estimations, I would like to first clarify a few terms to make sure we’re both on the same page regarding the important details. There are 3 points I’d like to clarify:
- Earl Grey tea is any tea marketed as such, regardless of the ingredients.
- British people consist of inhabitants of the UK.
- The consumption is measured in cups.
Do you agree with me on these assumptions?
<assume the interviewer agrees>
It’s great to see we understand the question the same way. For this question I’d like to take a few moments to gather my thoughts and draw up my issue tree – so may I take a timeout?
<assume the interviewer agrees>
<draw this issue tree>
Thanks for your patience.
Now, to estimate the consumption of Earl Grey tea by British people on a typical afternoon, I’d like to break it down into three determinants – the population of the UK, the number of tea cups each UK resident drinks in an afternoon, and the chance of those cups being Earl Grey.
For the population of the UK, I’d take a rounded number of 65 million.
In the average afternoon, each of these 65 million people drinks one cup of tea in their afternoon-tea meal, since the cup is quite large – about the size of a cup of coffee.
The chance of this cup being Earl Grey is 10% – Earl Grey is among the top 5 popular teas in the UK, and I estimate this group to take up 50% of all UK tea, considering so many other types in the market. The rounded number of 10% is taken to simplify the calculations.
Combining these numbers, I estimate that on a typical afternoon, British people consume 6.5 million cups of Earl Grey tea – quite an attractive number for any business operating in the tea industry.
Question 10 – How much is MConsultingPrep worth?
This is a “business valuation question”, where you estimate the monetary value of a business, and it’s a blend of guesstimation/market-sizing, math, and business. This also requires basic finance knowledge.
There are three ways to estimate the value of a business:
- The NPV Method: Take the net cash flow generated by the business, and discount it to the present to account for time value of money. Basically “this company is worth X dollars because it gives me Y dollars over Z years”.
- The Net Assets Method: Take the total assets of the business and minus its liabilities. In essence, “this company is worth X-Y dollars because it owns X dollars and owes Y dollars”.
- The Market Method: Take one index of the firm (which can be stocks or anything depending on the industry)and multiply it with an industry multiple (the value of one unit of the said index). In other words, “this company is worth AxB dollars because it has A traffic and each traffic is worth B dollars”.
Now to answer the given question:
“Thank you for the interesting question. Since MConsultingPrep is an established firm within the consulting prep niche, providing stable income for its shareholders, the NPV method should be the most suitable for this website. For this I would like to know the expected cash flow from MConsultingPrep, and the market interest rate – if this was a real project I would interview the client CFO and perform press search for these insights […]”
Question 11 – What do you see from the following chart?
Read more: Consulting & Case Interview Math
These chart-insights questions are among the most popular questions in case interviews (because we consultants run through mountains of charts and tables on a daily basis). Chart-reading is covered in my Comprehensive Math Drills along with mental calculations and case math.
One key note here: always add at least one “so-what” to your answer – to a consultant, data means nothing without implications.
While we’re in this pandemic together, let’s try this COVID-19 chart:
I’ll give you an example answer:
“Thank you for this very interesting piece of data. From this chart I can see a very steep rise around March 11 in the number of COVID-19 confirmed cases – from a negligible number to about 2,800 per million in just 5 months, along with a steady rise in the number of confirmed deaths to about 70-80 per million; both changes started around March 10-11. There are two implications from these data: 1. These sudden rises can be explained by events occurring in early-March, and 2. if we can keep the number of cases low, the threat from COVID-19 will remain minimal, considering a mortality rate of only 2%.”
Question 12 – What will a customer consider when buying a high-performance laptop?
This kind of question is called “value proposition question” – proposing values that the client can use to sell their products.
The most common mistake for this question type is to list out values straight-away – it makes you sound less structured and less insightful. Personally, I use a “double issue-tree” – essentially a table with customer segments on one axis and proposed values on the other:
“Thank you for the interesting question. To answer this question in the most MECE and insightful way, I would first segment the customers into High-End, Mid-Range, and Entry-Level according to their budget, then assess their preferences on three proposed values: Performance, Design, and Build Quality […]”
Question 13 – How do you find out a local customer’s preferences when buying a laptop?
These “information questions” essentially ask if the piece of data you use is obtainable in the first place. In real consulting work, data is not always available – client team members may refuse to cooperate or there’s simply no data on the subject.
There are many kinds of information sources in case interviews/consulting works, but I’ll divide them into primary and secondary sources. Primary sources means you must do the research yourself (or pay someone else to do it for you), such as customer surveys or mystery shoppings. If someone already did that research, and you use their results, it’s called a secondary source – you can get these from the client, the consulting firm you work for, or third-parties such as market research firms or external industry experts.
For these questions, you need to structure your answer as much as possible, and explain why you choose certain information sources over others.
You can find out more about these sources and how to cite them in real case interviews through this free Prospective Candidate Starter Pack, which contains a glossary of data sources in consulting.
And here’s how you should answer the example question:
“If this was a real project, I would find industry reports to gain initial understanding of the market trends, and in case I needed more and deeper insights, I would try to contact a local industry expert. The former method is quick and widely available but everyone can gain access to industry reports – including the competitors – and the information is not too insightful. Industry experts, on the other hand, can give unique insights that are not always accessible.”
Question 14 – How many units more does the client have to sell to break even?
These are math problems – not as complicated as the ones back in school, but they do require you to be quick and accurate with mental math, familiar with large numbers as well as basic business concepts. You also have the pressure of a high-stake interview (it’s easy to make mistakes when under stress).
Also try to “calculate out-loud” – these math questions can take quite long and it’s bad to leave long periods of silence.
Question 15 – What solutions do you suggest our client to recover the lost revenue?
Again, the biggest mistake a candidate usually makes at these “solution-finding questions” is to present solutions in a bottom-up manner without structuring them first.
If you can’t think of a more relevant way to segment your solutions, group them into short-term and long-term ones. It helps you brainstorm more thoroughly and makes a good impression on the interviewer. Just like this:
“To address the root cause of our client’s revenue problem, I suggest 2 long-term and 3 short-term solutions. The long-term solutions are 1 […] and 2 […]. The short-term ones are 1 […], 2 […], and 3 […]”
Question 16 – How do you present your solution to the client CEO in 30 seconds?
It’s called the “elevator pitch” – the hypothetical situation is that you must deliver the most important answer within an elevator ride with the client.
For your pitch to “pass”, it must be solution-oriented – the client CEO is busy, so he/she has no time for a full presentation. Just throw out the most important conclusions first, any questions can wait.
“Mr CEO, it’s been a pleasure to work with you on this interesting project of […]. Through rigorous research we have identified the root causes of [problem] to be: 1 […], 2 […]; here are the solutions we recommend to address that problem: 1 […], 2 […]. We would be more than happy to continue with you in future projects to implement those solutions.”
Question 17 – How do you put a giraffe inside a fridge?
Read more: Brain Teasers
Open the fridge, put the giraffe in, close the fridge. Nobody says how big the giraffe or the fridge is.
This kind of question is called “brain teasers” – invented by Google, they used to be popular in interviews at consulting and tech firms – that is, until Google themselves found out brain teasers were only effective for confusing the candidate and making the interviewer feel smart. Nonetheless, brain teasers might still appear in your consulting interviews.
Most brain teasers are trick questions (excluding one type – logical brain teasers) – and while people say answering these questions depend on pure luck and innate skills, they can be categorized and prepared for in a systematic way – as laid out in this article. Brain teasers do not take much effort to learn, so spend some time to prepare for them – just in case.
Note: Candidate-led cases and Interviewer-led cases
In candidate-led case interviews, where the candidate moves through the problem-solving process with the interviewer only as the “case universe operator”, the questions are seamlessly integrated in a gradual flow (see this Candidate-led Case Interview Example for further insights).
In interviewer-led cases where the interviewer commands the problem-solving process, the questions are more disconnected, however, they tend to exist in the same case universe, meaning you need to use the insights from one question to answer another.
You are now the interviewer. And the interviewer has become the interviewee. It’s your turn to ask them about their job, and their firm.
And you SHOULD ask questions – well-thought questions informed by prior research, presented in a structured manner, supported by equally poise follow-up questions, not just any questions. It shows that you really care about the job, that you did your homework, and you have the necessary mindset for the management consulting job.
Something like this:
“Before I applied, I talked to [name of consultant] who used to work at [name of office]. He told me that consulting requires two main skill sets, which he calls “substance” – basically the research and analysis work – and “people skills”. I believe these two skills sets do not contribute equally in one’s performance, so I have two questions:
- In this particular office, how much each of these skill sets contributes to high performance? Please quantify it into rough percentages if possible.
- In the case I get the offer, which skill can I focus on beforehand and during the first project? I am a fan of the 80-20 principle, so I want to identify the best leverage to improve my performance at the job.”
Then here’s how NOT to do it:
“Would you mind telling me what skills are important for this job?” (It sounds like you’ve done no research and just asked the question for the sake of not staying silent)
The same thing applies to networking interviews – which you can read more about in this article.
And voila! You’ve just passed the hardest job interviews in the market (if you manage to nail every question type I’ve mentioned!).
However, one important note for this article is that later rounds of the interview process (with higher-level consultants) can be quite unpredictable – and to prepare for such situations you need to master the fundamentals of the case interview. Such fundamentals are covered in my Case Interview End-to-End Secrets Program, as well as this free comprehensive guide.
Once you master the principles of the case interview, it’s time to practice a real-life case interview! Schedule a meeting with former consultants who have interviewed thousands of candidates. They have the insider knowledge to help you ace an interview.