Taking an example, "Children vaccine" case, I wonder how we structure the case, whether it use the same structure (MECE or issue tree) like other types of case or we use the different structure for market sizing case.
Schedule mock interviews on the Meeting Board, join the latest community discussions in our Consulting Q&A and find like-minded Interview Partners to connect and practice with!
Back to overview
14
How to structuring the market sizing case?
1
4.8k
Be the first to answer!
Nobody has responded to this question yet.
Top answer
Vlad
on Aug 28, 2018
Coach
McKinsey / Accenture Alum / Got all BIG3 offers / Harvard Business School
Hi,
First of all, market sizing can be either a part of the case or a standalone case.
Secondly, It's less about different types of the problems but rather about the tools that you use:
1) First of all, there are 2 ways to structure market sizing:
- Formula - basically a math formula to come up with a solution. The problem with the formula is that it is easy to forget something or get lost.
- Tree - same as with regular cases you build a tree. A very simple example: you need to calculate the number of dogs on manhattan. A number of dogs = share of households having a dog * # of households. # of households = population / average household size. In the end, you'll have a pyramid where you have to fill the numbers on the base of the pyramid. This approach is much easier and help you track all the numbers
2) You should learn the key market sizing techniques:
- Making assumptions based on personal experiences (Use the example of your house where out of 100 apt-s 10 have dogs)
- Adjusting numbers (NY is a busy city thus fewer people have dogs)
- Sanity check - try to apply your calculations to the real environment
- etc.
3) You should learn the key tools:
- Using age even age split (suppose life expectancy is 80 years. Assuming even age split we have 4 mln people in US of each age)
- Using 80/20 split (suppose 20% people earn 80% wealth and the average salary is xx...)
- Using approximations (Length of NY-SF flight and plane speed to calculate US length)
- etc.
4) Learn key numbers: populations, gas price, gas consumption, Boeing speed and nmber of seats, average salary, # of gates in the airport, GDP growth rate, inflation, etc.
5) Practice 10-15 cases and you'll be fine. Almost all casebooks have good market sizing examples and the solutions
Feel free to PM for clarifications
Good Luck!
0 comments
Similar Questions
Most Popular Posts
Skill/Level differences
9
on Oct 11, 2025
Middle East
5
100+
Top answer by
Sidi
Coach
McKinsey Senior EM & BCG Consultant | Interviewer at McK & BCG for 7 years | Coached 500+ candidates secure MBB offers
5 Answers
100+ Views
+2
Trouble with brainstorming
13
on Oct 12, 2025
USA
8
100+
Top answer by
Sidi
Coach
McKinsey Senior EM & BCG Consultant | Interviewer at McK & BCG for 7 years | Coached 500+ candidates secure MBB offers
8 Answers
100+ Views
+5
Final question to ask to the interviewer, MCK
13
on Oct 12, 2025
Europe
6
200+
Top answer by
Seongyun
Coach
Current OW Interviewer | Offers from McKinsey, OW, All Big 4 Strategy Houses | CV & Cover Letter Review
6 Answers
200+ Views
+3
Cover letter advice
8
on Oct 13, 2025
Middle East
6
100+
Top answer by
Evelina
Coach
EY-Parthenon l Coached 100+ candidates into MBB & Tier-2 l 10% off first session l LBS graduate
6 Answers
100+ Views
+3
McKinsey Offer Negociation
9
on Oct 18, 2025
Europe
7
100+
Top answer by
Sherif
Coach
Ex Sr. Engagement Manager with McKinsey - Aug 25 - Top EEMA interviewer 2023 - 2024 with +350 interviews
7 Answers
100+ Views
+4