The 1-Day Case Interview Prep Plan

Only have 1 day to prepare for your consulting interview? The majority of candidates require significantly more time than a day to prepare, with 6-8 weeks of prep recommended. However sometimes the reality and circumstances may leave you with only a day before your interview. 

In this situation, here’s a suggested approach to maximize your preparation time, assuming you have only have 1 day to prepare, or roughly ~6-8 hours. The following is of course a guideline and can be adjusted based on where you think you might need to spend more/less time. 

🤖 In addition, Given the short amount of time, I would suggest using AI/ChatGPT to enhance your preparation, and you can read about how to do so here: How To Use AI to Enhance Your Consulting Interview Preparation

1. Consulting Interview Overview [30 Mins]

Before jumping into practice, take a bit of time to understand what a consulting interview actually looks like – it’s quite different from a typical corporate interview!

Start by watching one or two short sample videos of real case interviews. This helps you get a feel for the flow, tone, and what interviewers are really looking for.

Next, take a look at the diagram below – it gives you a clear overview of how a consulting interview is usually structured. You’ll see that it’s divided into four main parts:

• Intro (1–2 mins): A short warm-up to get comfortable.
• Fit / Behavioral (10–15 mins): Questions about your background, motivation, and soft skills.
• Case Problem (25–30 mins): The main part of the interview, where you solve a business problem together with your interviewer.
• Questions (3–5 mins): Your opportunity to ask the interviewer about their work or the firm.

Understanding this structure will make your preparation much more focused – you’ll know exactly what’s coming and where to spend your time and energy.
 

2. Fit / Behavioral Part [30 Mins]

Before jumping into cases, get comfortable with the Fit Interview – this is where interviewers learn about you as a person.

Use the STAR method (Situation, Task, Action, Result) to keep your answers structured and clear.
Prepare two short stories (2–3 minutes each):

• One for a personal motivation question (e.g. “Why consulting?”)
• One for a behavioral question (e.g. “Tell me about a time you showed leadership.”)

🫱 Check out our article on fit interviews!
 

3. Case Problem: Structuring [1.5 Hour]

Structure is everything in a case interview. Start by reviewing three go-to frameworks:

• Profit Tree
• 3 Cs (Customer, Competition, Company)
• Internal vs. External

Once you’re familiar with them, apply these frameworks to a couple of sample case prompts – for example, using PrepLounge or ChatGPT. The goal isn’t to memorize, but to get comfortable thinking in clear, logical steps.

🫱 Access hundreds of real consulting cases!
 

4. Case Problem: Math [1 Hour]

Math is a big part of every case interview – but don’t worry, it’s more about being quick and confident than about complex formulas. Review your basic arithmetic (addition, subtraction, multiplication, division) and make sure you can handle calculations on paper.

Then, practice around 20 short math drills to warm up. Tools like PrepLounge or ChatGPT can generate exercises that help you pick up speed and accuracy.

🫱 Get your mental math skills up to speed
 

5. Case Problem: Business Judgment & Concepts [1 Hour]

Beyond the numbers, interviewers want to see if you understand how businesses actually work. Refresh your knowledge of the basics – how revenue is driven by price and quantity, how costs split into fixed and variable components, and what breakeven really means.

Knowing these simple but powerful ideas will help you make sense of data and spot what’s driving a company’s performance.

🫱 Learn the fundamentals in our Case Interview Basics
 

6. Case Problem: Market Sizing [30 Mins]

Market sizing questions test your logic and structure under pressure. Learn the top-down approach – start with a big number and narrow it down step by step. Do one quick practice case to get the hang of it, and focus on explaining your thought process clearly as you go.

🫱 Check out our article on Market Sizing!

7. Case Problem: Chart Interpretation [30 Mins]

Charts appear in almost every case, and they’re not about memorizing numbers – they’re about telling a story. When you see a chart, take a moment to clarify what’s being asked, understand the axes and labels, and then highlight what stands out.

From there, summarize your insights in one or two sentences and suggest what you’d explore next.

🫱 How to interpret charts and data

8. Practice Mock Interviews [2 Hours]

Wrap up your prep with two mock interviews – ideally with a partner on PrepLounge. After each one, note down feedback and reflect on what to improve next time.

🫱 Schedule mock interviews with peers on the Meeting Board

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