I only have 5 hrs to prepare for market size. I have done tones of Cases but non market size. Any tips?

Hi there,

With 5 hours, focus on the basics that will cover 80% of what you need.

1. Learn the core approaches
Top-down (start from population or macro data, narrow down with assumptions) and bottom-up (start from individual usage or sales, scale up). Be comfortable switching between them.

2. Practice 3–4 classic drills
Size the market for coffee in your city, the number of gas stations in the UK, or annual revenue for Netflix. Time-box each to 15 minutes, then review your logic.

3. Focus on structure, not the “right” number
Interviewers care more about how you break down the problem and justify assumptions than the final figure.

4. Keep math clean and round
Use easy numbers (e.g. 50 million instead of 48.7 million) and sanity check at the end.

If you do this for a few hours, you will walk into the interview with enough confidence to tackle most market sizing questions.

Best of luck!

Hi there,

With 5 hours, you don’t need to overcomplicate things—just get comfortable with a simple, repeatable structure. The core formula you mentioned is spot on:

Market size = Volume × Price × Frequency

Here’s how to use it under pressure:

1. Pick an anchor (volume):
   • Start with population or number of customers/companies.
   • Narrow down logically (e.g., % urban, % with access, % likely to use product).
2. Estimate frequency of use:
   • How often does the customer buy/use it per year/week?
   • Anchor with everyday logic (e.g., coffees per day, Uber rides per week, dentist visits per year).
3. Add price per unit:
   • Keep it simple—round numbers to make math fast.
   • If you don’t know, use reasonable proxies (e.g., taxi fares for Uber, fast food meal price for Deliveroo).
4. Cross-check:
   • Ask yourself: does the result feel too big or small compared to GDP, industry reports, or common sense?
   • If yes, adjust one assumption.

Tips to practice in 5 hours:

• Do 3–4 drills on everyday markets (coffee in your city, Uber rides in London, toothpaste in Europe, etc.).
• Always state assumptions clearly (“Let’s assume…”). That matters more than the exact number.
• Round numbers aggressively (work with 50M instead of 47.3M).
• Talk through logic before doing math, so your structure shines even if your arithmetic is slightly off.

This way, you’ll show interviewers you can reason, structure, and sanity-check—even if you’ve never memorized a framework.

Happy to help you prep – feel free to reach out.

Best,
Evelina