What market share does our client need to be profitable?
This question chains two calculations. The first gives the revenue needed to cover fixed costs, by dividing them by the contribution margin rate. The second relates that revenue to the size of the market. The real answer is the judgment that follows: is that share reachable against incumbents?
What the interviewer is assessing
- That you see the chain. Candidates looking for a single formula get lost. Those who announce "first required revenue, then share" move through it easily.
- That you use the margin rate and not gross revenue. Each euro sold only partly contributes to covering fixed costs.
- That you interpret the share you get by comparing it with competitors' shares and how long it took them to get there.
How to build your answer
- 1
Gather three figures
Annual fixed costs, the contribution margin rate and the size of the market, in the same unit and over the same period. - 2
Calculate required revenue
Fixed costs divided by the margin rate. At a 40% rate, it takes 2.50 euros of sales to cover 1 euro of fixed costs. - 3
Relate it to the market
Required revenue divided by market size. Use simple fractions to go fast. - 4
Judge the result
Compare with current players' shares, with the market the client can actually reach and with the time it gives itself.
How a good answer starts
"I will go in two steps: calculate the revenue the client needs to cover its costs, then relate it to the market. You give me 12 million euros of fixed costs a year and a contribution margin of 40%. So the revenue needed is 12 divided by 0.4, which is 30 million euros.
The market is worth 400 million. 30 over 400 is 3 over 40, or 7.5%. On its own that figure looks modest, but I would like to put it in perspective. You mentioned that the third player in the market holds about 10%: our client would have to get close to its size just to avoid losing money, which is ambitious for a new entrant. I would also check whether the full 400 million is accessible, because if half the market is locked into long contracts, the share to win in the rest is really 15%."
This example is made up: it shows the tone and the construction, not a script to memorise. Your answer has to come from your own experience or from the data the interviewer gives you.
Common mistakes
- Dividing fixed costs directly by market size, forgetting that only margin covers costs.
- Slipping on the division by a percentage. Dividing by 0.4 is multiplying by 2.5: having that reflex avoids the error.
- Stopping at the percentage without saying whether it is realistic.
- Reasoning on the total market when only part of it is open to the client.
Follow-ups to expect
"And to make 6 million in profit?"
Add the target profit to fixed costs before dividing: 18 divided by 0.4 gives 45 million, a little over 11% of the market.
"How long would it take to reach that share?"
Reason from the pace of customer acquisition and from what comparable entrants achieved, asking for data if needed.
Frequently asked questions
What is the contribution margin rate?
It is the part of each euro of sales left once the costs that vary with volume, such as materials or commissions, are paid. That part goes to covering fixed costs, then to profit.
What if the market size is not given?
Estimate it yourself with a quick market sizing, stating your assumptions, then pick the calculation back up. The two exercises often follow each other within one case.