The case interview, and how to prep
A case interview hands you a business problem to solve out loud with the interviewer: clarify the goal, structure it, ask for data, do quick math and make a recommendation. Consulting firms use it to see how you think. Good prep is those few skills practiced aloud until they are automatic, then full cases with someone who pushes back.
Updated
- One problem, out loud. Structure it, ask for data, do quick math and recommend.
- A few kinds. You lead or the interviewer leads, plus market sizing, online and written cases.
- Reasoning counts most. BCG and Bain say there isn't always one right answer.
- Four weeks. About an hour a day: drills alone, then full cases with pushback.
- Free cases. From the firms themselves. McKinsey alone posts six.
What a case interview is
Bain calls it a structured conversation where you work through a real business problem. McKinsey calls it the problem-solving interview, and BCG uses it for client-facing roles. You get a short prompt, then data when you ask for it, and the interviewer listens to how you reason more than to the final number.
The kinds of case interview6 kinds
You lead
Candidate-led
After your structure, you choose which branch to explore, ask for the data you need and decide when to move on. The interviewer answers and nudges.
They lead
Interviewer-led
The interviewer asks a set of questions in turn, such as your structure, a chart to read and a calculation. Answer each one fully and sum it up before the next.
Case interview questionsEstimate
Market sizing
How big is a market, or how many of something are sold. It comes alone or inside a bigger case. State the approach, then the numbers, then check the result makes sense.
Market sizing questionsOn screen
Online case
Solved alone before the live rounds, such as McKinsey's Solve game, BCG's Casey chatbot case and Bain's digital assessment for some applicants.
How BCG's Casey worksOn paper
Written or presentation case
A pack of slides or data to read alone for a set time, then a recommendation you present and defend. Ask your recruiter which format to expect.
Beyond consulting
Cases at banks and tech
Capital One runs case interviews for analyst roles, and product teams use product cases. Same skills, different problems.
Capital One case interview
The five parts of every case5 parts
1. Clarify
Make sure you know the goal
Say the question back in one sentence and ask two or three questions about the objective and the business. Bain's first tip is to clarify the objective.
2. Structure
Split the problem
Take a moment, then lay out the three or four things you would need to know. McKinsey asks for tailored answers rather than standard frameworks.
How to build an issue tree3. Analysis
Ask for data and read it
Ask for the numbers your structure needs, read charts and tables, and say what each one means for the question, not only what it shows.
4. Math
Calculate out loud
Say the approach before the numbers, then check the answer is sensible. BCG expects quick calculations and warns against rushing.
Free case math drills5. Recommend
Answer first
Give the answer, two or three reasons with numbers, the main risk and the next steps, in under a minute.
A worked example, start to finish5 steps
A regional bakery chain's profit fell from $10 million to $8 million in a year. The CEO wants to know why, and what to do.
1. Clarify
Say the goal back, then ask
"So we want to find why profit fell 20% and how to win it back. Has anything changed, such as new stores, products or prices?" The interviewer says it is the same 50 stores and the same menu.
2. Structure
Split the problem
"Profit is revenue minus costs, so first I'll find which one moved. Revenue is customers times spend per visit. Costs are ingredients, labor and rent."
3. Analysis
Ask for data and say what it means
The interviewer shows revenue up from $100 million to $104 million and costs up from $90 million to $96 million, with labor and rent flat. "Revenue grew 4%, so this is a cost problem, and all $6 million of the rise is ingredients."
4. Math
Size it out loud
"Ingredients rose 17%, from 36% of revenue to about 40%. To earn $2 million more on $104 million of sales, prices would need to rise about 2%, if customers buy the same amount."
5. Recommend
Answer first, then reasons and risk
"Profit fell because ingredient costs rose $6 million while sales grew only 4%. I'd raise prices about 2% on the items with the highest ingredient cost and renegotiate flour and butter contracts. The risk is customers buying less, so I'd test the new prices in a few stores first."
From Bain, McKinsey and BCG's case interview pages.
What case interviewers look for
The firms describe the same few things. Reasoning matters more than reaching one right number.
A structure built for this case
McKinsey asks you to listen carefully and give a tailored answer rather than a standard framework.
Your thinking, out loud
BCG lists showing your thinking and communicating clearly, and warns against staying silent.
The goal and assumptions first
Bain's tips start with clarifying the objective. BCG asks you to clarify assumptions and ask thoughtful questions.
Quick, careful math
BCG expects quick calculations and warns against rushing or overcomplicating the answer.
From McKinsey, BCG and Bain's case interview pages.
A 4-week case interview prep plan
About an hour a day. Short drills you can do alone, then full cases with a partner or an AI interviewer.
Show the four weeks
Week 1
Learn the shape of a case
Read two firm sample cases end to end, such as McKinsey's Beautify and Bain's Coffee Shop Co. Learn the common case types and do ten minutes of case math every day.
Week 2
Structure out loud
Two case openings a day: read the prompt, take a minute, then say your structure aloud in under two minutes. Compare it with the strong opening on the question page.
Week 3
Full cases with pushback
Three or four full cases with a partner or an AI interviewer who asks follow-ups. After each one, write down the single thing to fix next time.
Week 4
Your target firms and your story
Practice in the style of the firms you applied to, keep the math sharp, and prepare the fit stories that come in the same interviews.
20 practice cases by type
The case types that come up most, with what a strong opening does. Each has a note on what a strong opening does.
Profitability4 cases
Revenue or costs, and which moved.
A regional grocery chain's profits are down 20% in two years. Why?
Show follow-ups
Split profit into revenue and costs, then ask which moved before guessing why. Practice it, see a model answer
An airline carries more passengers but makes less money. What is going on?
Show follow-ups
Volume is up, so look at price per seat and cost per seat, and ask for the numbers to compare. Practice it, see a model answer
A software company grows 40% a year and still loses money. What would you do?
Show follow-ups
Separate the cost of growth from the cost of running the business, then look at what a customer is worth. Practice it, see a model answer
One of three divisions is losing money. Fix it, sell it or close it?
Show follow-ups
Set out what each option is worth, including costs the division shares with the rest of the company. Practice it, see a model answer
Market entry and growth5 cases
Is the market worth it, and can the client win there?
A European e-bike maker wants to enter the US. Should it?
Show follow-ups
Market size and growth, competitors, the client's edge, and the way in, ending in a clear yes or no. Practice it, see a model answer
A US coffee chain is considering India. How would you approach it?
Show follow-ups
Show you know the customer is different, then test whether the economics of one store work. Practice it, see a model answer
A gym chain wants to double revenue in five years. How?
Show follow-ups
Break the goal into more members, more per member and more locations, and size each lever. Practice it, see a model answer
A streaming service's churn has doubled in a year. How do you find out why?
Show follow-ups
Ask who is leaving and when, then test price, content and competition against that. Practice it, see a model answer
Brainstorm ways a movie theater chain could grow revenue.
Show follow-ups
Group the ideas before you list them, so the answer reads as a structure, not a pile. Practice it, see a model answer
Pricing3 cases
Value to the customer, cost, and what competitors charge.
How should a software company price a new add-on?
Show follow-ups
Start from the value to the customer, then check it against cost and competing products. Practice it, see a model answer
The main competitor just cut prices by 20%. How should the client respond?
Show follow-ups
Find out why they cut and who switches before recommending a match, a hold or a new offer. Practice it, see a model answer
Should an airline raise its checked-bag fee?
Show follow-ups
Weigh the extra fee revenue against the passengers and bags it would lose. Practice it, see a model answer
Deals and investments3 cases
What it is worth, what it costs, and what could go wrong.
A PE firm is considering buying a chain of dental clinics. Should it?
Show follow-ups
Market, the business itself, the price and the exit, with the biggest risk named. Practice it, see a model answer
Two regional airlines want to merge. How big are the savings?
Show follow-ups
List the synergies by type, size the largest ones and say what could stop them. Practice it, see a model answer
Should a manufacturer build a second factory?
Show follow-ups
Demand it would serve, cost and payback, and the cheaper ways to get the same capacity. Practice it, see a model answer
Operations and public sector2 cases
Find where the process breaks.
A hospital's emergency room waits have doubled. How would you approach it?
Show follow-ups
Follow a patient through the stages and find the one where time has grown. Practice it, see a model answer
A city wants to halve traffic deaths in ten years. Where do you start?
Show follow-ups
Who dies, where and how, then the measures that address the largest groups first. Practice it, see a model answer
Math and market sizing3 cases
State the approach, then the numbers.
How many cups a day does a new coffee shop need to sell to break even?
Show follow-ups
Fixed costs over the margin per cup, with each assumption said out loud. Practice it, see a model answer
Estimate the US market for electric scooters.
Show follow-ups
Pick top-down or bottom-up and say why, then sanity-check the result. Practice it, see a model answer
The CEO walks in. What is your recommendation?
Show follow-ups
The answer first, two or three reasons with numbers, the risks and the next steps. Practice it, see a model answer
What the firms say about the case
From each firm's own careers pages. None publishes a scoring rubric or how many cases to practice.
McKinseySix sample cases
Calls it the problem-solving interview: a typical client scenario to see how you approach complex problems. It recommends practicing its sample cases and says there is no one logical solution, so listen carefully and tailor your answer instead of using a standard framework.
McKinsey: InterviewingBCGDos and don'ts
A realistic business challenge worked step by step: structure your approach, ask questions, analyze data, do quick calculations and find what matters most. It looks for clear communication, logic, business intuition and creativity, and says there isn't always a single right answer.
BCG: Case interview preparationBainSample cases and tips
A structured conversation about a real business problem that shows how you think and build on ideas. Its tips: clarify the objective, structure your thinking, think aloud, and listen and adapt to the interviewer. It publishes sample cases such as Coffee Shop Co. and FashionCo.
Bain: Case interviewHow to choose your case prep
Good prep gives you three things: real cases, someone who pushes back, and honest feedback on what you said. Five kinds of help can give you those. Choose by how many weeks you have, what you can spend and whether you have a partner. Most candidates combine free cases with one or two ways to get feedback.
Free cases and casebooksFree
The firms' own sample cases, such as McKinsey's six and Bain's Coffee Shop Co. and FashionCo., plus casebooks that business school consulting clubs publish with cases and model answers.
- Pros
- Free, close to the real format, and the firm's own cases show what each one values.
- Cons
- Reading a case is not practicing one. Casebook answers vary in quality, and you still need someone to play the interviewer.
- Who it suits
- Everyone, first. Read two firm cases before you pay for anything.
Peer practiceFree
Classmates, a consulting club or other candidates take turns giving each other cases, one as candidate and one as interviewer.
- Pros
- Free, a real person across the table, and giving cases teaches you what interviewers listen for.
- Cons
- Feedback is only as good as your partner, friends tend to be kind rather than useful, and schedules get hard close to interviews.
- Who it suits
- Anyone from week two or three, as the main source of full cases. Agree on what to score before you start: structure, math, a clear recommendation.
CoachesBy the hour
A former consultant or interviewer runs full cases with you one to one and tells you what to change, often including your fit stories.
- Pros
- Human judgment from someone who has sat on the other side, feedback aimed at you, and pushback that feels like the real thing.
- Cons
- Quality varies a lot between people, it is the most expensive option per case, and you only practice when a session is booked.
- Who it suits
- Candidates with one clear weakness to fix, or anyone who wants one or two full human mocks in the last week.
CoursesOne fee or monthly
Video lessons or a program that teaches the case types, a way to structure them, case math and worked examples, sometimes with a question bank.
- Pros
- A clear method fast, worked examples to compare with, and drills to practice.
- Cons
- Watching is not practice, and a memorized framework can turn into a template. McKinsey asks for a tailored answer rather than a standard framework.
- Who it suits
- Beginners in the first week or two who want the shape of a case laid out.
AI mock interviewsTrial, then monthly
An AI interviewer gives you a case out loud, asks follow-ups, shows data and then scores what you said. You can practice at any hour, as often as you like.
- Pros
- Full cases on demand, follow-up questions every time, math checked as you go and a report after each case. McKinsey lists practicing interview questions with AI as encouraged.
- Cons
- It is not a human judging your presence in the room, and tools differ. Check that it pushes back and asks for your reasoning rather than letting you talk.
- Who it suits
- Daily reps between partner sessions in weeks two to four, and anyone without a regular partner.
For example, Soreno (that's us) runs full cases in your browser: an AI interviewer that asks follow-ups, shows charts, checks your math and scores the session, free for 7 days. Try a free sample case
Costs are in general terms because they change.
Practice a full case, out loud
Soreno's AI interviewer runs a whole case with you: it asks follow-ups, shows charts, checks your math and scores the session. Free for 7 days.
Questions people ask
What is a case interview?
A job interview where you solve a business problem out loud with the interviewer: clarify the goal, structure the problem, ask for and read data, do quick math and recommend what to do. Consulting firms use it for client-facing roles, and some banks and tech companies use it too.
Is a case interview the same as a case study interview?
Mostly. BCG calls it a case study interview and McKinsey calls it a problem-solving interview. Outside consulting, a case study interview can also mean a take-home exercise you present later.
How long does case interview prep take?
No firm says. Four weeks of about an hour a day is enough for the plan above. If you have less time, keep the daily math and spoken openings and do fewer full cases.
How many practice cases should I do?
Firms don't publish a number, and the count matters less than what you fix after each case. Go on until your openings are clear on the first try and your math holds up under questions.
Do I need to memorize frameworks?
No. McKinsey asks for tailored answers rather than standard frameworks. Learn the usual parts of a case, then build a structure for the problem in front of you.
Can I prepare for case interviews alone?
Partly. Math, market sizing and spoken openings work alone. Full cases need someone to push back, a partner or an AI interviewer.
Can I use a calculator in a case interview?
Practice without one. McKinsey says calculators are not allowed in its assessments unless the instructions say so, and case math is meant to be done by hand.
Is it fine to use AI to prepare?
Yes. McKinsey lists practicing interview questions and asking AI to explain frameworks as encouraged, and generating answers during a real interview as not allowed.