What Is a Case Interview? Format, Example and How to Prepare

A case interview is a job interview in which you are given a realistic business problem, such as falling profits or whether to enter a new market, and asked to work through it out loud with the interviewer. It tests how you structure an unclear problem, analyze data, do quick math and reach a recommendation.

Management consulting firms rely on case interviews most heavily, and product management, strategy and some finance and operations roles use their own versions. As of October 2026, McKinsey, BCG and Bain describe the format in similar terms on their own candidate pages:

• McKinsey calls it the Problem-Solving Interview, which it says is sometimes referred to as a case interview, and pairs it with a Personal Experience Interview (McKinsey's interviewing guide).
• BCG says you get a realistic business challenge to structure, question, analyze and calculate your way through, and that what matters most is how you approach the problem and the quality of your reasoning (BCG's case interview preparation page).
• Bain says case interviews are mainly for consulting roles, typically after a digital assessment, and that it wants to see whether you can think in a logical and structured way (Bain's interviewing page).

How a case interview works

Formats differ by firm and interviewer, but most live cases follow six steps:

1. The prompt. The interviewer describes a client and a question, such as "Should our client launch a budget airline?" or "Why are profits down?"
2. Clarifying questions. You confirm the objective, scope and time frame before you start solving.
3. Structure. You lay out how you will break the problem down, often as an issue tree, and walk the interviewer through it.
4. Analysis. The interviewer shares data, such as a chart or a table, and you explain what it means for the question.
5. Math. You run quick calculations, such as percentages, growth, breakeven or a market-size estimate, and say each step out loud.
6. Recommendation. You close with a clear answer, the two or three reasons behind it, the main risks and the next steps you would take.

Prep guides often describe two styles. In a candidate-led case you decide which branch to explore next; in an interviewer-led case the interviewer steers you through a set sequence of questions. Practice both, and ask your recruiter which to expect.

Common types of case

• Profitability: why profits fell and how to restore them.
• Market entry: whether a company should enter a new market, country or product line.
• Market sizing: estimating a number you can't look up, built from stated assumptions.
• Investments, pricing and growth: whether to buy a company, how to set a price or how to grow revenue.
• Product cases: in PM interviews, how you would design, improve or measure a product (see our product manager interview questions guide).

What a case interview looks like: a short example

Example we wrote for illustration. It is not taken from any firm's question bank.

Prompt: "Our client runs 40 gyms. Revenue has been flat at $50 million a year for two years, but profit has fallen from $5 million to $4.25 million. What's going on, and what should they do?"

1. Clarify. "Is the goal to get profit back to $5 million, and over what time frame? Has anything changed, such as new locations or opening hours?" The interviewer says there are no new locations and the goal is to recover within a year.
2. Structure. "Profit is revenue minus costs. Revenue is flat, so I'll focus on costs, split into fixed costs like rent and staff, and variable costs like utilities and marketing."
3. Analysis. The interviewer shares a cost table: rent is up $0.2 million, staff costs are up $0.6 million and other costs are down $0.05 million.
4. Math. "Profit fell by $0.75 million, which is 15%. Costs rose by the same $0.75 million, and staff costs explain $0.6 million of it, or 80%." The interviewer adds that 10 gyms moved to 24-hour opening last year.
5. Recommendation. "Staffing the longer hours is the main driver. I'd check visits per hour at those 10 gyms and cut staffed hours where late-night use is low, which targets most of the $0.6 million. The risk is losing members who value 24-hour access, so I'd test it at two or three sites first."

What earns credit: a structure that fits the facts, math said out loud, and a committed answer with a risk and a next step.

Case interview vs behavioral interview

Consulting interviews often pair a case with fit questions. Our guide to what a behavioral interview is covers that half.

How to prepare for a case interview

1. Start with the firms' own material. McKinsey, BCG and Bain all publish case preparation pages, and McKinsey's guide points you to sample cases with suggested answers.
2. Build structures; don't memorize them. Learn the common case types, then practice drawing an issue tree that fits each new prompt. McKinsey's guide notes there is not one logical solution, so reciting a stock framework rarely impresses.
3. Drill the math. Practice percentages, growth rates, breakeven and estimation by hand until you can do them while talking.
4. Practice live with a partner. Run full cases with another candidate or a mentor and swap roles; playing the interviewer shows you what a clear structure sounds like.
5. Rehearse a 30-second close. End every practice case with a recommendation you can say in one breath: answer, reasons, risks, next steps.
6. Prepare the fit half separately. Draft five or six stories about leading, persuading and recovering from setbacks with the free STAR story builder, then say them out loud.

For spoken practice of the fit questions, the free browser AI mock interview needs no install and includes behavioral and product tracks. CoPilot Interview's desktop Mock Interview builds questions from your résumé and the job description, and scores each spoken answer out of 10 with what to fix and a model answer. It does not run consulting cases, so pair it with a human case partner. Our consulting interview page covers how firms' rounds differ.

Common case interview mistakes

• Forcing a memorized framework onto a problem it doesn't fit.
• Diving into numbers before agreeing on the goal. A minute of clarifying questions can save ten minutes of solving the wrong problem.
• Calculating in silence. Say each step so the interviewer can follow you and correct you early.
• Ignoring the data. When the interviewer shares a chart, say what it changes about your answer.
• Ending without a recommendation. "It depends" is not an answer. Commit, then name the risk.
• Neglecting the fit questions. A strong case won't rescue a vague story.

See what happens in a final round interview, or browse more terms in the AI interview glossary.

FAQ

How long is a case interview?

It varies by firm, round and role. Many consulting interviews combine a case with fit or personal-experience questions in the same session, so ask your recruiter how long each interview runs and how the time is split.

Do you need a business degree to pass a case interview?

No. Firms present the case as a test of reasoning: BCG says what matters most is how you approach the problem and the quality of your reasoning. You do need basics such as revenue, costs and margins, which practice cases teach.

Can you use a calculator in a case interview?

Plan not to. Live cases usually expect quick math on paper or in your head while you explain each step. Online tests and written cases can differ, so check your invitation.

What is a market sizing question?

A market sizing question asks you to estimate a number you can't look up, such as how many electric bikes are sold in a city each year. You build it from stated assumptions, such as population and the share of people who cycle, then check the result is plausible. The reasoning matters more than the number.

Are case interviews only used in consulting?

No. Consulting firms use them most, but product management interviews use product cases, and strategy, corporate development and some finance and operations roles use business cases or take-home case studies. The core skills are the same: structure, numbers and a clear recommendation.