How much time does someone need to prepare for McKinsey/Bain interviews?

Hi there! 

While every candidate is different, I thought I'd share some (hopefully helpful) perspective/ general benchmarks that I've personally experienced in preparing for interviews at top management consulting firms. 

Here's what to expect if you're still more of a beginner at case interview prep (if you're already more experienced, you can certainly adjust accordingly from here):

• Recommended prep time: beginners typically need several weeks of focused preparation, often around 6-8 weeks or ~60+ hours, to be ready for consulting case interviews at MBB (McKinsey, Bain, BCG) and other top firms. I've seen many successful candidates invest even more time than that (sometimes 100+ hours over 2-3 months) to reach a high proficiency level. As a part of that time, expect to practice roughly 30-50 mock cases, which is a key part of prep since each case practiced builds skills and confidence that is hugely valuable for real interviews. 

  • Key takeaway: aim for at least ~60+ hours and 30-50 mock cases to prepare for MBB interviews.

     

• Self-study alone is not sufficient. Reading case books, learning frameworks, and going through cases on your own is valuable for building fundamentals, but nothing replaces live mock interviews with partners or coaches. Mock interviews train you to solve problems out loud, under time pressure, and with interactive feedback, which mirrors what actual interviews test. And sure, while only part of a mock session is spent solving a case, the rest (feedback, discussion, role reversal), if done well and efficiently, is critical learning time that sharply improves your performance. For example, I recommend spending ~15–20 minutes debriefing each 30–40 minute practice case to maximize learning.

  • Key takeaway: use self-study to learn basics and drill skills, but prioritize mock cases (30-50 of them) to develop interview-ready skills.

     

• 3 weeks @ 1 hour per day (i.e., ~21 hours) is likely too little for MBB interviews. Top consulting firms have a high bar; most successful candidates prepare ~60 hours (often more) for case interviews, and typically only very exceptional candidates with strong business intuition or prior experience might pull off an offer with such limited prep. That said, if you literally only have ~3 weeks to prep, try to increase your daily hours and focus intensely on high-quality practice; if I'm being brutally honest, you should treat that limited time as an emergency, full-on sprint. Focus on quality over quantity: use resources that teach you the core skills quickly (for instance, an accelerated case course like the ones available on PrepLounge). Then dive into mock interviews immediately – perhaps start with a friend for comfort, then quickly move to practicing with other candidates or coaches who can challenge you. Identify your biggest weakness early (maybe your math, or structuring, or communication) and concentrate on fixing that, rather than trying to cover every possible case type superficially. It’s also wise to temper expectations: with only 3 weeks, you might not reach the polish of someone who prepared for 2 months, but you can still make significant improvement if you’re disciplined. And if you do secure more time (e.g. interview gets postponed), use it fully.

  • Key takeaway: ~21 hours is generally too little for an average beginner aiming for MBB; aim for ~60 hours (or more) if you can.

     

Hope that helps! Feel free to reach out with questions or concerns; I'd be happy to setup a free intro call to help you craft a custom plan for success with whatever prep time you have available.


Best,
David

Hi There,

There are lots of great responses on here! I would echo similar sentiment around needing 30-50 cases and that prepping just by yourself is not enough.

You want to practice as close to the real interview as possible, which means casing with peers or coaches.

-This will provide you with actual feedback as it is easy to overlook your own shortcomings are flaws when you are just prepping by yourself.

-You have a higher likelihood of practicing with a wider-variety of cases that will challenge you.

-It is also imperative that you get used to casing with a wide variety of individuals since everyone has a slightly different style of casing, especially when interviewing with partners. They tend to have a bit more flexibility on how they go about conducting the interview and case, so feeling comfortable going through that uncertainty will also be a massive boon to your preparation.

Outside of just casing you need to spend time on prepping for the behavioral/fit portion of the interview. This goes especially for McKinsey since they have their PEI portion. Do NOT underestimate the amount of time it will take to prepare for the PEI as many candidates end up crushing the case but struggling on this portion. Expect to be putting in at least 10-20 hours of prep into just PEI prep.

Hope this helps and happy to chat if helpful!

-Ankit A

Hi there,

First of all, congratulations on the (presumed) invitations from McKinsey and Bain!

I would be happy to share my thoughts on your questions:

• First of all, since you are certainly right to state that peer practice is not the most efficient way, you have two more options: friends and family, and an experienced coach like myself. In any case, I would strongly advise you to stay away from practicing on your own, as it is not efficient and doesn't simulate the actual interview situation properly.
• Moreover, instead of thinking about the bare minimum required to succeed in the interviews, I would strongly advise you to shift your mindset to ensuring that you eliminate any reason to reject you that is in your control as soon as possible. There are still enough reasons to reject candidates that are out of their control.

You can find more on this topic here: How to succeed in the final interview round.

If you would like a more detailed discussion on how to best prepare your application files, for your upcoming pre-interview assessments and/or interviews, please don't hesitate to contact me directly.

Best,

Hagen

Hi there, 

Preparing on your own would not be enough. In the real interview you have to face an individual who you most likely have never met before - you need to be trained in such setting, and be able to handle the interaction / engagement with the interviewer. It is very different to it in real vs. imagining it in your head. Consider getting a coach if you find the peer mock interviews are not giving you the best use of time (who you mock with makes a bit difference). 

3 weeks of 1 hour per day (21 hours in in total) is too little prep. For a candidate to get well prepared, the minimum # of practices would be 25-30 mock cases. And to make each practice really count, it is not only the 1 hour you spend doing the mock and discussing the feedback - candidate should do multiple rounds of review / reflection afterwards to internalize the learning. From my experience, candidate should spend 3x the time on each case practiced to get the max value from the practice. In addition, besides just mock case, candidate should also spend time to hone communication skills, get more prepared with some business, finance and industry fundamentals. So in total, it definitely requires more than 21 hours. 

Best,

Emily

3 weeks of 1 hour a day is  too little unless you are in the small minority of people that have a very strong natural affinity for casing. If you only have 3 weeks before an MBB interview, see if you can ask the recruiter to delay. Most people take 6 weeks+ to get interview ready.

I would strongly suggest that you do a combination of solo preparation (to understand core concepts and do drills), peer prep (for case interview reps), and coaching (to quickly accelerate your progress).

Obviously I am biased, but coaching is by far the highest ROI time spent, since good coaches have actually interviewed MBB candidates and know how the process works back-to-front

Hi!

1) you should mix mocks, drills and coaching sessions. Solo practice is more effective after getting good feedbacks from trustworthy partners/professionals.

2) too little, really. Most people spend 3+h a day for 2-3months. At least for MBB. If you have great business acumen or is naturally good at casing (rare), the time needed will be lower. A coach also may have a big impact on the time needed, accelerating your learning curve.

My advice: Find videos of ex consultants solving cases on YouTube. Try to tackle them and compare your answer to theirs. That may give you an idea on where you’re at and what your weak spots are.

Happy to work with you to accelerate your learning process.

Best,

Mari

Hey there,

3 weeks with 1h/day can work if you're already structured and just polishing. But if you're starting from scratch, it's likely too short, most people need at least 30–40 hours total to get confident.

Solo prep helps a lot for math, structures, and drills. But for real progress, do a few targeted mocks to test pressure, communication, and adaptability, even 5–6 good ones can make a big difference.

Let me know if you want help planning your prep!

best,
Alessa :)

Hi there, 

Honestly, it varies a lot, but if you're looking for a gross average, it's about 100h of prep, typically spread across 2-3 months. 

This would include a combination of individual prep, peer prep and coaching sessions. 

Can you do it on your own? Yes. But most people opt for a coach because it increases their chances of success from <5% to >60-80%. 

Best,
Cristian

Hi there,

1) Is preparing on my own enough? 

You might be able to land an offer by preparing on your own, however, you will probably learn more/have a more efficient preparation if you practice with good peers/coaches/current consultants.

2) How much time should I realistically invest before starting the interview process? Would 3 weeks of 1 hour per day be too little?

Starting from zero, it is not uncommon to have to dedicate 100+ hours preparing for interviews, although it might be less with coaching or good material. If you have already done some prep, 20 hours could be enough, but if you are starting from scratch, you will probably need more time.

Good luck!

Francesco

Hi,

The million dollar question.. there are of course averages, but really what is most important is to understand where you stand and what are your gaps, then you can figure out how to best prepare. 

I've known candidates who have aced the interview without any preparation (literally), and i've known candidates who have aced the interview after ~9 months of prep (or even longer).

What matters to you is a personalized perspective, not an average!