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BCG Case Interview Examples: A Worked Practice Case

BCG cases are candidate-led and hypothesis-driven, and interviewers reward creative, insightful thinking. Work through a full BCG-style growth case step by step, check your math as you go, and compare your answers to a model response.

By the Case Prep Team Updated October 1, 2026 16 min read

Candidate-ledYou drive the structure

2 roundsTypical after online assessments

CaseyOnline case used for screening

Hypothesis-drivenThe style BCG rewards

Start the practice case Read the BCG interview guide

Format

What makes BCG cases different

BCG cases are candidate-led: you set the structure and drive the analysis. What sets BCG apart is how much it values insight. Interviewers want to see you form a view early, test it with data, and come up with ideas that go beyond the obvious.

Hypothesis first

Strong BCG candidates say what they think the answer might be, then explain which analysis would prove or disprove it. It keeps the case focused and shows judgment.

Creativity counts

BCG interviewers often ask open questions like "what else could the client do?" and reward ideas that are both original and practical. A structured brainstorm beats a long list.

Online assessments come first

Most candidates complete online assessments before live interviews, including the Casey online case in many offices. Prepare for these separately from your live case practice.

BCG is one of the three MBB firms, alongside McKinsey and Bain, and the formats differ in important ways. McKinsey runs interviewer-led cases, while BCG and Bain expect you to drive. See the McKinsey and Bain case examples to compare.

Case types

Case types BCG candidates report

These five themes cover most BCG cases. Each example prompt below is an original BCG-style prompt, not a real interview question. Pick a tab to see how you would structure it and what math to expect.

Example prompt: A specialty coffee chain's growth has stalled at 200 stores. How can it grow again?
How to structure it: Split growth into existing stores (traffic, ticket size, new products) and new stores (new cities, new formats like kiosks). Size each and rank by impact and risk.
Math to expect: Revenue per store, like-for-like growth, and payback on new sites.

Practice case

Worked practice case: Helio Power

This is an original case written in the style BCG candidates describe: market sizing, a unit economics exhibit, a business case, and a creative question. In a live interview you would drive the structure yourself. Here, each step shows the question an interviewer would likely ask next.

Answer each step out loud or on paper before you reveal the model answer. The suggested times match a strong candidate's pace.

Market entryEnergyAbout 25 minutes

Helio Power: should a utility install rooftop solar?

Your client is Helio Power, an electric utility serving 4 million households in the US Southwest. More customers are installing rooftop solar through independent installers, which cuts the electricity they buy from Helio. The CEO is considering whether Helio should enter the rooftop solar installation market itself. She has asked BCG for a recommendation. How would you approach this?

If you ask clarifying questions, the interviewer shares:

Regulators allow Helio to run an installation business separately from its utility business.
The average home system sells for $20,000 installed.
The CEO wants the business to be profitable within three years.

0 of 6 steps revealed

Structure the problem

Take about 2 minutes

Interviewer: How would you approach this?
My hypothesis is that Helio should enter, because it has an advantage independent installers lack: a relationship with every household in its territory. To test that, I would look at:
- Market: how many homes install solar each year, and how fast that is growing.
- Competition: who installs today, how fragmented the market is, and what customers care about.
- Economics: profit per installation for Helio compared with independent installers.
- Strategic fit: whether entering protects or hurts the core utility business, and what regulators would allow.
Why it works: leading with a specific hypothesis, and naming the advantage you expect to matter, is exactly the BCG style. It tells the interviewer what you plan to prove.
Size the market

Take about 3 minutes

Interviewer: How many dollars a year are spent on rooftop solar installations in Helio's territory?

Annual market ($M)
Build it from households:
- 4M households, and about 60% are owner-occupied single-family homes that could install solar: 2.4M homes.
- Assume about 2% of those install each year: 48,000 installations.
- At $20,000 each, the market is 48,000 times $20,000, or about $960M a year.
That is large enough to matter, and adoption is rising, so the market should grow from here.

Saying each assumption out loud lets the interviewer correct you early. A clean, logical build matters more than the exact number.

Read the economics exhibit

Take about 3 minutes

Interviewer: Here is the cost breakdown for a typical installation. What profit would Helio make per installation, and why is it different?

Exhibit 1: Cost per $20,000 installation

Cost line	Independent installer	Helio (estimate)
Panels and equipment	$9,000	$9,000
Installation labor	$4,000	$4,000
Customer acquisition (sales and marketing)	$3,000	$1,000
Overhead	$1,000	$1,000
Total cost	$17,000	$15,000

Illustrative data for practice.

Helio profit per installation ($)

Size the business case

Take about 3 minutes

Interviewer: If Helio wins 10% of the installations in its territory, how much annual profit would the business make?

Annual profit ($M)
Think creatively

Take about 3 minutes

Interviewer: Beyond installing panels, how else could Helio make money from rooftop solar?
I would group ideas by what Helio could sell around the panels:
- Products: home batteries, which store solar power for evenings, and EV chargers sold alongside solar.
- Financing: loans or leases that let customers pay monthly, which also widens the market to people who cannot pay $20,000 upfront.
- Services: maintenance plans and performance monitoring.
- Grid value: pay customers to share stored battery power during peak demand, turning thousands of homes into a "virtual power plant" that saves Helio from building new capacity.
The virtual power plant idea is the kind of insight BCG interviewers remember: it turns a threat to the utility into an asset for it.
Make the recommendation

Take about 1 minute

Interviewer: The CEO walks in. What do you recommend?

Math

BCG case math quick check

BCG math is rarely complex, but it moves fast and often sits inside an exhibit. Try these four without a calculator, and aim for under a minute each.

A city has 500,000 households. 30% own a car, and 4% of car owners buy an EV each year. How many EVs are bought each year?

EVs per year

A company's costs are $45M on $60M of revenue. What is its profit margin?

Margin (%)

A new store costs $1.5M to open and earns $600K a year in profit. What is the payback period?

Payback (years)

Market share rises from 12% to 15% in a $2B market. How much extra revenue is that?

Extra revenue ($M)

Assessment

Before the interviews: Casey and online tests

Most BCG candidates complete online assessments before any live interview. Formats vary by office and role, and candidates report several:

Casey: a single online case delivered by a chatbot, commonly reported as about 25 to 35 minutes with 8 to 10 questions. It ends with a short window to prepare and a recorded video recommendation of about a minute. Because Casey controls the order of questions, it feels closer to an interviewer-led case.
Consulting Career Assessment: some candidates also take this separate test, which combines problem-solving questions with questions about how you work.

The skills overlap with live cases, but the format does not. Practice doing case math quickly and writing short, clear answers without an interviewer to guide you. The BCG interview guide covers the current assessments in detail.

Prep plan

A two-week prep plan for a BCG case

Days 1 to 3
Practice opening every case with a hypothesis and a tailored structure. Start with the frameworks guide.
Days 4 to 6
Drill market sizing and exhibit math daily until both feel fast.
Days 7 to 8
Practice creative questions: give three to four groups of ideas in under two minutes, and flag the most promising one.
Days 9 to 11
Run full candidate-led cases with a partner. Redo Helio Power from memory and time yourself.
Days 12 to 14
Prepare fit stories and a specific "Why BCG?" If your office uses Casey, do a timed online case on your own.

Keep preparing

BCG interview guideRounds, assessments, and fit questions. Free BCG style caseA full practice case in BCG's format. McKinsey case examplesA worked interviewer-led case. Bain case examplesA worked candidate-led case.

FAQ

Frequently asked questions

Are BCG case interviews candidate-led?

Yes, mostly. You set the structure and drive the analysis, though interviewers share data and steer you as the case goes on.

What is the BCG Casey online case?

Casey is an online case delivered through a chatbot, used by most offices to screen candidates before live interviews. You answer a series of questions on one business problem, then record a short video recommendation.

What kind of cases does BCG give?

Growth, market entry, profitability, pricing, and public sector cases are all common. BCG cases often include an open question that tests creativity.

How is BCG different from McKinsey and Bain?

McKinsey runs interviewer-led cases with a fixed question sequence. BCG and Bain expect you to drive. BCG puts particular weight on hypothesis-driven thinking and creative insight.

How many rounds does BCG run?

A typical process has two rounds of live interviews after the online assessments, each with cases and fit questions.

Is the Helio Power case a real BCG case?

No. It is an original practice case written to match the style BCG candidates describe. All numbers are illustrative.

Sources

Hacking the Case Interview, BCG Case Interview: Complete Prep Guide. hackingthecaseinterview.com. Accessed October 2026.
Management Consulted, BCG Online Case: Casey Chatbot Interview Guide. managementconsulted.com. Accessed October 2026.
Road to Offer, BCG Case Interview Guide 2026. roadtooffer.com. Accessed October 2026.

Case Prep is an independent practice platform and is not affiliated with, authorized by, or endorsed by Boston Consulting Group. The Helio Power case, example prompts, and all data on this page are original teaching material.