Market sizing case: how many petrol stations are there in the US?

Case case study Market sizing
New answer on Oct 11, 2023
6 Answers
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Anonymous A asked on May 10, 2017

How would you approach this case?

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Content Creator
replied on May 12, 2017
5+ Years at BCG & Kearney Dubai & Istanbul | 400+ Trainees | Free 15-min Consultation Call

Hi Anonymous,

As mentioned earlier, there are many different ways one can approach this problem. I typically approach this following way:

1. What is the total demand for gas stations?

2. What is the demand for one gas station?

3. -> Find the total number of gas stations

To start with number 1, while I have no idea about the real numbers, let's assume that population is 400M, and there is 1 car per 4 people. Thus we would have 100M cars.

Now we need to estimate the total demand for a day/week/year, let's go ahead with day. From my personal experience, I visit gas stations once every two weeks. Assuming this is the case for the entire population, 100M cars would visit gas stations every two weeks. This means that about 7M cars visit gas stations every day. -> This is the total demand.

Now we are at number 2, we need to understand the number of cars visit a gas station during one day. To keep it simple, we can assume (again, based on personal experience) that there are always 3 cars occupying the gas station for 5 minutes throughout 18 hours (and the remaining of the time, the gas station is empty). This would give us ~600 cars every day. -> This is the demand for one gas station.

We can find the number of gas stations by diving total demand (7M) by local demand (600), and reach ~12000 as our final answer.

I have quickly checked on google, and the real answer is about x10 higher than my answer. HOWEVER, it really is not important to get a precise answer to impress the interviewer. It is all about sharing your train of thought and laying out your assumptions very explicitly.

I hope this was helpful.

Have a good day,

Deniz Ahmet

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Rahul on Dec 26, 2019

why did you ignore commercial vehicles?

Jason replied on May 10, 2017
Case leader, MBB

There are infinite ways to size it so the following is by no means an exact answer. My preferred method would be to initially segment by locality, given that the drivers of demand for a petrol station are significantly different between rural areas and population centers.

Stations in rural areas are driven by the average range of a car when they need to refuel, so you could derive a number through the station density and area of America.

Stations in population centers are driven by the demand (i.e. the number of cars) in each city. I would actually segment this down further into Metropolises/Cities/Towns given the large difference in population size between them. Also, you would need to factor in that these stations are nowhere near running at full capacity.

I appreciate any feedback on this approach.

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Content Creator
replied on Oct 11, 2023
ex Jr. Partner McKinsey|Senior Interviewer|Real Feedback & Free Homework between sessions|Harvard Coach|10+ Experience

Hi there,

Population and Car Ownership: I would assume a population of approximately 330 million in the US. To estimate the number of cars, I would assume that, on average, there is one car for every 2.5 people. This would give us roughly 132 million cars in the US.

Daily Visit Frequency: I would assume that, on average, a car visits a petrol station every three days. This assumption is based on typical driving habits and the need for refueling.

Capacity of a Petrol Station: Assuming each petrol station can serve 500 cars in a day, given the number of fuel pumps and the station's operating hours.

By multiplying the number of cars by the visit frequency and dividing by the capacity of a petrol station, I can estimate the total number of petrol stations needed. Using these assumptions, the calculation would look like this:

(132 million cars / 3 days) / 500 cars per station per day = 88,000 petrol stations

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Anonymous B replied on May 16, 2017

I would think how many petrol stations are in a specific region. For example, you know that in the city you live in there are 6 petrol stations. Let's say the city has 30 000 people, so that results to about 5000 people per petrol station. US has about 300million people, so divide 300m/5000 and you get 60 000 petrol stations.

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Anonymous updated the answer on Dec 24, 2022

I like answer 1!

There are more detailed ways but I like this approach because you give a quick answer and then you can walk your interviewer how you refine these high-level assumptions.


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Content Creator
replied on May 28, 2020
McKinsey | Awarded professor at Master in Management @ IE | MBA at MIT |+180 students coached | Integrated FIT Guide aut


To add on top what´s been said, you can also do it from:

# vehicles > # liters each of them consume > averge need for a gas station.

You can also use 1 method and the 2nd one to proof it.



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Deniz gave the best answer


Content Creator
5+ Years at BCG & Kearney Dubai & Istanbul | 400+ Trainees | Free 15-min Consultation Call
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