Do you need to ask the interviewer if each of your assumptions sound reasonable and wait for a yes before you use them? For eg if you assume 80% of the population can afford this product and give a reason why, then you ask if they are ok with this assumption and only proceed if you get a green signal? Or should you do the full market sizing just stating your assumptions and rationale without waiting for a green signal on whether they are reasonable?
Back to overview
10
4
Mkt sizing assumptions
2
1.7k
Be the first to answer!
Nobody has responded to this question yet.
Top answer
Ian
on Aug 16, 2021
Coach
Top US BCG / MBB Coach - 5,000 sessions |Tech, Platinion, Big 4 | 9/9 personal interviews passed | 95% candidate success
Hi there,
You should not do this.
One of the main points of market sizing is to assess whether you can approach the problem and make reasonable assumptions on your own.
The interviewer will not help you here and it's up to you to make reasonable assumptions, assess them, and drive the market sizing forward based on what you know about the world!
0 comments
Deleted user
on Aug 20, 2021
Hello,
Don't ask the interviewers or wait for a green light - proceed with the full market sizing stating your assumptions and rationale. If needed, the interviewer will stop and correct you, but usually they won't because they care more about your thought process and rationale than the actual numbers you come up with.
Sign up for free to read all answers.
Sign up for free to read all answers.
Similar Questions
Most Popular Posts
I got fired from a T2 and struggling to find a job
10
on Apr 16, 2026
UK
8
100+
Top answer by
Franco
Coach
Ex BCG Principal & Global Interviewer (10+ Years) | 100+ MBB Offers | 95% Success Rate
8 Answers
100+ Views
+5
Not getting responses from LinkedIn outreach or post-event follow-ups — what am I doing wrong?
15
on Apr 17, 2026
USA
8
100+
Top answer by
Soheil
Coach
INSEAD | EM & Strategy Consultant | 3.5Y Consulting | 5★ Case Coach | 350+ Cases | 50+ Live Interviews | MBB-Level
8 Answers
100+ Views
+5
Hypothesis ( bcg style )
9
on Apr 18, 2026
Middle East
8
100+
Top answer by
Franco
Coach
Ex BCG Principal & Global Interviewer (10+ Years) | 100+ MBB Offers | 95% Success Rate
8 Answers
100+ Views
+5
Struggling with structuring + final recommendations in case interviews
8
on Apr 18, 2026
USA
9
100+
Top answer by
Tommaso
Coach
Ex-McKinsey | MBA @ Berkeley Haas | No-nonsense coaching | 50% off on 1st meeting in April (DM me for discount code!)
9 Answers
100+ Views
+6
Question: "Is there something we haven't asked you that we should?"
9
on Apr 20, 2026
Europe
10
200+
Top answer by
Soheil
Coach
INSEAD | EM & Strategy Consultant | 3.5Y Consulting | 5★ Case Coach | 350+ Cases | 50+ Live Interviews | MBB-Level
10 Answers
200+ Views
+7