In reviewing the hundreds of thousands of emails I’ve received in the past 10 years, one of the most common questions I am asked is how much time is needed to prepare for a case interview and how to prepare when you don’t have much time.

I want to address in this article the 2nd question of how to prepare for a case interview when you don’t have much time.

I am going to share with you several emails I have received from readers all on this topic along with my answer and my tips for how to best prepare while under a time crunch. I am putting these in order of least amount of time to practice (10 hours) to most (2months) in case you are in a time crunch you can go to the section that most applies to your situation.

Reader #1: Only 10 Hours Available to Practice Before Interview

I’m about to go through the case interview at McKinsey next Friday. As you will realize, I don’t have much time left. I work full time and then try to prepare myself for the interview in the late afternoons.

Can you advise me on which videos to focus on considering the time available? I will have full Thursday to spend practicing and half Friday.

My answer:

Go through all the Case Interview Secrets videos in the order they are listed.  This should take about 5 – 6 hours. If you have time left over, either:

1. Practice some cases with a current/former consultant or a very talented friend who is also recruiting,


2. Get Look Over My Shoulder®, skip most of the recordings, focus only on cases #3, #4, and #5 and only listen to the very last candidate in each case.

These are best practice interviews that demonstrate how to do a case the right way.

This should take about three hours.

(Note to others: If you know you have more than three hours prep time, I would not recommend jumping to these cases. I would recommend going through the cases in the order listed.)

The two aspects of LOMS you would be missing in this approach are:

a) Hearing how people tend to make mistakes in cases (so you can learn to recognize the early warning signs of these mistakes in your own performance and avoid them)


b) The benefit of repetition and reinforcement

But if you only have 10 hours, you have to sacrifice something, and that is what I would sacrifice.

Reader #2 – 3 Days Until Interview

I have a BCG interview in a few days.  I just started to prepare last week when I found out (I was really surprised and elated to get the interview). I’m going to try to read all of Case in Point by tomorrow, and I am almost done watching your videos.  What do you think is the best usage of my time?

I’m working really hard, on lots of caffeine, and trying to get on par with the competition! Hopefully there’s a chance for me and I appreciate any advice you can give me on how to maximize my time until the big day.  Thanks so much for your help!

My Response:

I would suggest the following:

1) Go through my videos so you get the gist of what’s supposed to happen during a case study interview.

2) Go through the frameworks handout and get familiar with them.

3)  Practice the two most common case types: client has profit problem, figure out why and what to do about it…. and new market segment / product entry business situation.

Do some case interview practice sessions with a buddy or if you don’t have access to a buddy, get a business magazine like Fortune or Business Week, and take all the market entry, new product successes/failures, profitability problem stories and run them through the frameworks.

You want to be able to take an amorphous business situation like should the NBA expand into China, and structure such a nebulous question into specific categories of key issues…. so that once you analyze each category of issue, the totality of your analysis would lead you to know what the client should do.

4) Practice estimation questions (I don’t cover these in my video… but google it for examples). Basically, practice multiplying large round numbers in your head… like 100 million households x 2.0 children x 2 shoes per child per year…. the market size of children’s shoes is 400 million pairs… x $25 = $10 billion market.

It’s very easy to get confused with all those zeros (these day’s I’m terrible at it, so if you don’t use it, you definitely lose it… so practice those).

Note: For every 3 – 4 business cases, you’ll get an estimation question. Sometimes an estimation question will naturally come up in the middle of a business case (It definitely comes up all the time on-the-job with a client). So practice for the full blown cases first as they occur more often, then practice the estimation question cases.

If you did all of that in the next 72 hours, that would be a pretty good plan.

Reader #3 – 4-5 Days Until Interview

With only four days to go before my Monitor interview (which came about randomly after applying months ago), what is the best way to do case interview preparation?

My Response:

Four days is not a lot of time, as you will be competing against people (especially anyone who follows my advice and happened to find my materials early in their recruiting process) who have been preparing for several months, and often up to a year.

If you are very serious about doing well on this interview, here is what I suggest, to maximize your chances of success in such a short period of time:

Cancel everything else on your calendar.  Aim to do ten hours of prep on this per day, add in some breaks, and basically you’re going 12 – 14 hours per day.  Make sure you get enough sleep.

If you are tired, you will not learn as quickly. If you are tired during your interview, it is hard to perform well.  My advice is 12 -14 hours per day, assuming you have nothing else on your calendar.  And get a good night’s sleep the night before your interview.

I almost blew my McKinsey Final Round #2 (I had two final rounds) because it was in New York City, I had to fly in, and because of the time zone shift, I was unable to go to bed early… but still had to wake up really early… so I slept maybe four hours.

Of all my rounds of interviews, it was my worst — just off here and there.  But it was good enough to pass, and considering I already passed my Los Angeles final round, I think they kind of just gave me the benefit of the doubt.

Moral of the story get some sleep.

If you are working full time and doing this much, it is too much — cut it in half.

What follows is a day-by-day plan.

** Day 1**

If you have not already, go through the free Case Interview Secrets videos (if you have already gone through those recently, you can just go ahead and use the Day #2 activity plan as your Day #1).

This will give you the key concepts, and help you intellectually understand what you are supposed to do.

** Day 2 **

Go through Look Over My Shoulder® one time — should take you about 12 hours.  LOMS is not a “how to” program. It is designed as a practice, repetition, reinforcement program.

In this program you will see 13 different candidates in real-world environment mock interviews.

(Even though they were not real interviews, people took them very seriously, including flying across the U.S. at their own expense, just to do the one interview with me in person.)

The purpose of LOMS on this day of the plan is to see how the concepts (that seem so easy and obvious in my slides during the Case Interview Secrets videos) get complicated in a real world setting.

** Day 3 **

If you have access to a friend who can give you a case interview practice case, this is a good day to do several practice cases — ideally 1 – 3 cases.

This should take you a half day, depending on scheduling. In your downtime on this day, get a head start on the Day 4 plan, as the Day 4 plan is a very long day.

The purpose of the live case interview practice interviews is to see how many of the good habits you picked up from LOMS, and what natural tendencies you have, in terms of bad habits.

If there are five key skills to doing a case interview well, most people with sufficient preparation can get pretty good at four out of the five skills.

But, there’s usually one skill that lags behind. So the purpose of the practice interview is to get better at the four out of five skills, and to find which skill is your one problem area.

Usually for this skill, you have to “unlearn” what you instinctively want to do, and “re-learn” the right way to do it.

This is often more time consuming than not knowing anything, and learning it correctly the first time without having to unlearn the wrong way first.

It is very hard to predict which area will be your problem area.

** Day 4 **

Go through LOMS a second time (and possibly start on a third time if you finished Day 3 early). This time, instead of listening at broad level, this time listen to the cases with a deep focus on your problem area.

And as you listen to the case, rather than just listen passively, this time actively listen for what each candidates says, and every four minutes assess whether the candidate is doing it right or not.

This is very important.

(If you only listen or read the LOMS materials, you only get half the value. You have to use the LOMS by engaging with it.  That is how you get the most value out of it.)

If you think they did it wrong, pause the recording and say out loud (I know it sounds a little silly, but trust me, it is very important especially given your time frame.

You need to be very deliberate about moving conceptual knowledge into auditory skills.  You can’t just think the right way, you have to think the right way and say it the right way…).

If after hearing my assessment, you discover it did not match yourassessment, then use the explanation I gave for what the candidate should have done instead, and then you say out loud what the better approach would have been.

If in your live practice, you have a really hard time being thorough in asking for data, pay attention to how the candidates in LOMS did or did not ask for data correctly. If you have a bad habit of not using a hypothesis correctly,then focus on that.

** Day 5 **

If you were able to skip Day 1 because you did it already, then I would try to split this day — half live practice with a partner, half LOMS using the same approach as on Day 4.

If you do not have access to a practice partner who is him/herself strong enough at cases to be able to give you a case, then just go through LOMS as described in Day 4.

Also to the extent you have or anticipate interviews with other firms, you can take the approach above and everywhere it says Day 1, Day 2, etc… just change it to Week 1, Week 2, etc..

After Day 5, you basically want to alternate between LOMS using the “active” approach and live practice, depending on your time and availability of a practice partner.

Also, if you do not have access to a practice partner for live cases, then just go through LOMS as an alternative.

I believe that a balance between LOMS and live practice is the ideal combination, but a fair number of people do not have access to practice partners, so additional LOMS repetition is the recommended alternative.

Based on the success stories I get from people via email, the best practice is to go through LOMS five times in the “active” way to get an offer.

Many people are not able to do this before their first interview. So I will commonly hear, “LOMS was great, I only had X days to practice and I passed (barely).

“I got feedback from my interviewer in Round 1 that I need to work on Y skills (structuring, hypothesis, math computations, synthesis, etc…) and will focus on that in going through LOMS a few more times before next week’s Round 2.”

In four days, it’s impossible to master the case study interview process.

It is possible (barely) to get good enough to pass a Round 1 when your competition is the weakest (compared to the other rounds).

Reader #4 – 2 Months Until Interview

I have an interview in 2 months with McKinsey, which is a good thing. The problem is I had rejections from BCG, Bain and Booz and I didn’t succeed my first interview with Monitor! In result, I lost my confidence and my head is muddled!McKinsey is all what I want and this is my last chance…
What do you think about my situation, do you think that I can make it?

My Response:

If you are getting interviews with the Top 3, it’s very likely it’s within your ability to pass. It’s also a good thing you have two months to prepare, as you will definitely need it given where your current performance is at.

Here is what I suggest.

Focus only on my Case Interview Secrets book. All the books out there tend to conflict with one another and if you try to combine them all, it does not work.

Work on your mental math. Go to and use the free practice tools. In consulting, mental math is considered basic. If you make a math mistake, you’re automatically rejected 90% of the time. Practice a little — even 10 minutes – every day.

If you are very serious about passing, there are two others resources I would suggest. The downside is they do cost some money, but they are very helpful.

The first is my Look Over My Shoulder® (LOMS) program. It includes examples of excellent, okay and poor case performance, and my real-time explanation as to why certain sentences the candidate said were incorrect, or sub-optimal. The CIB who becomes F1Y — the majority have used LOMS for 50 – 100 hours (basically listening to it over and over again to grasp the correct way of doing things).

After you use LOMS and after practicing with some friends on practice cases, you might consider getting a few practice interviews with my coaches. They are ex-Bain and ex-McKinsey consultants and interviewers. Maybe you are three interviews away from being able to pass, but if the real McKinsey interview is the only “real” interview you have coming up, you might just miss by a small amount.

Do the LOMS stuff first to fix all the basic mistakes, and use the coaching for fine tuning the subtle stuff.

By the way, a lot of LOMS users discover that what they thought was correct was actually incorrect… and discover why for the first time with LOMS.

Finally, I suggest using my Case Interview partner service to practice even more with live practice partners..

Good luck!