Market sizing case interview practice
Structuring an unfamiliar market, making defensible assumptions, calculating a sensible estimate and explaining its commercial meaning. Practise the 5 questions the real interviewer asks with follow-ups. Paid plans add scored feedback on every answer.
Free with an Intaviu account: 320 credits a month, at 10 credits a minute of practice. Private: interview creators never see them.
- 20 minutes
- 5 questions
- Scored feedback on paid plans
About this interview
A market sizing case tests how you turn a broad question into a defensible numerical estimate when complete data is unavailable. The interviewer is assessing your structure, mental maths, assumptions and ability to explain what the number means for a business decision.
How to prepare
- Practise both population-led and supply-led approaches to estimating a market.
- Refresh percentage, unit conversion and multiplication skills without relying on a spreadsheet.
- Build a habit of stating units and checking each calculation as you go.
- Prepare ways to test an answer against a familiar real-world benchmark.
- Practise ending with a short conclusion that includes uncertainty and the next data to collect.
Common mistakes
- Starting arithmetic before defining the market and the unit being estimated.
- Hiding assumptions instead of stating and defending them.
- Losing track of units, time periods or zeros during the calculation.
- Giving a final number without a plausibility check or commercial conclusion.
What to expect
A real mock interview
5 questions the way the real interviewer asks, with follow-ups when an answer needs more.
Spoken, like the real thing
Speak your answers in your browser or the free desktop app, with live captions. You can ask the interviewer to repeat anything.
Scored on 4 areas
The things this interview weighs most. With a paid plan, your report shows how you did on each one.
A private report
On Plus, Pro and Premium: every answer scored, your strongest lines quoted and what to say differently next time. Interview creators never see it.
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