If you’re thinking about a career in consulting, chances are you’ve come across terms like “Big Three” or “Big Four.” But what do they actually mean – and how are these firms different from each other?
Here’s the short version: The Big Three, also known as MBB, stands for McKinsey, BCG, and Bain – the three largest and most prestigious strategy consulting firms in the world. The Big Four – Deloitte, PwC, EY, and KPMG – originally come from accounting, but today they’re also major players in consulting.
A lot of aspiring consultants dream of landing a job at one of these big-name firms. But with so many different terms, it's easy to get confused. That's why you'll find an overview here of which company belongs to which category, what makes them special and why it's worth getting to know them – and help you figure out which firm might be the best fit for you.
Let’s start! 🚀
The “Big Three” are the three leading global consulting firms, namely McKinsey, BCG, and Bain & Company. They are each other's biggest competitors and have competed for customers for decades. Their extensive client base, reputation for delivering high-quality consulting services and global network of top consultants sets them apart from other consulting firms in the industry.
McKinsey was founded in 1926 and is widely recognized as one of the oldest, most prestigious, and most influential consulting firms worldwide. With more than 140 offices in 65 countries, McKinsey has a significant global presence and an expansive network that enables the consulting firm to serve clients from various industries on a global scale.
What Makes McKinsey Stand Out?
McKinsey’s advice often shapes major business decisions, public policy, and even large-scale social initiatives. The firm offers a wide range of consulting services – from strategy and operations to organization, tech, marketing, and sustainability.
Known for its deep industry expertise and thought leadership, McKinsey has established a strong reputation for its contributions to the business world. The consultancy conducts extensive research, publishes reports, and shares insights on critical business issues, trends, and new innovations.
Who Does McKinsey Hire?
McKinsey seeks to attract top talent from diverse academic backgrounds and industries. The consulting firm hires individuals with exceptional problem-solving skills, analytical abilities, and leadership potential. Senior consultants guide and coach their junior colleagues and support them in their professional growth and development within the firm. Moreover, McKinsey provides comprehensive training and development programs to build up the consulting skills of their employees. They are credited with recruiting and developing some of the top business leaders in the world and have earned the nickname “The CEO Factory” as top executives from companies such as Facebook and Google have come from McKinsey.
Want to learn more about McKinsey? Check out these helpful guides:
👉 McKinsey Case Interview
👉 McKinsey Internship Application Guide
👉 McKinsey Personal Experience Interview
👉 McKinsey Problem Solving Game
Bain was founded in 1973 by Bill Bain and a group of BCG executives after a fallout with the incumbent BCG CEO, Bruce Henderson. Bill Bain and his team had generated more than 50% of BCG’s annual revenues and after disagreeing with several Bruce Henderson’s management decisions, they resigned and started their own consulting firm, taking many BCG clients with them.
The firm grew rapidly and began to focus on a business turnaround strategy, working closely with private equity investors (including their own spin-off, Bain Capital). Today private equity makes up a large proportion of Bain’s annual revenues. By now, the consulting firm has grown to an annual revenue of more than $5.8bn and has over 64 offices in 39 countries.
What Kind of Projects Does Bain Do?
Bain & Company is regularly advised for driving successful turnarounds, launching new ventures, and guiding companies through periods of disruption. The consulting firm’s client portfolio ranges from startups to multinational corporations.
One of Bain’s biggest strengths is its work in private equity. Bain consultants support investors across the full deal cycle: from sourcing and due diligence to portfolio strategy and exit planning. If you're interested in the world of PE, Bain is one of the go-to firms.
What Is the Corporate Culture at Bain & Company Like?
Just as McKinsey and BCG, Bain emphasizes a strong corporate culture to attract talent from around the globe. Their employees are referred to as “Bainies” and the consulting firm promotes a highly collaborative work environment of mutual support and inclusion.
Moreover, Bain's culture encourages entrepreneurial thinking and initiative. Consultants are empowered to take ownership of their work, drive innovation, and proactively seek new opportunities for growth. “Results, not reports” is one of the core values of the consulting firm and a strong hands-on mentality as well as a focus on tangible results are actively encouraged.
Want to learn more about Bain? Check out these helpful resources:
👉 Bain Case Interview
👉 Bain Sova Test
👉 Career at Bain
The Boston Consulting Group (BCG) was founded in 1963 initially as the consulting arm of The Boston Safe Deposit and Trust Company in order to provide strategic advice to the bank's clients. Eventually, the employees purchased full ownership of the consulting practice and became BCG as it is known today.
By now, BCG has over 90 offices in more than 50 countries. It is recognized as one of the leading consulting firms worldwide and provides clients with strategic advice to drive growth, optimize operations, and navigate the ever-changing business landscape.
What Does BCG Focus On?
BCG’ focus is on strategic management consulting for organizations from various sectors, including financial services, industrial goods, retail, or the public sector. The consultancy is known for its innovative and forward-thinking approach, and delivery of tangible results.
Projects are often in the fields of growth strategies, market analysis, organizational change, and operational efficiency.
Boston Consulting Group supports clients in building digital strategies that use new technologies to improve customer experience and boost innovation. The corporate culture at the Boston Consulting Group is based on five principles: “Bring insight to light”, “conquer complexity”, “drive inspired impact”, “lead with integrity”, and “grow by growing others”. Teamwork, mentorship, and coaching are fostered to help consultants develop their skills and reach their full potential.
What Is BCG Looking for in Applicants?
As a top-tier professional services firm, BCG is always on the lookout for talented people to join their teams. They typically look for candidates with strong analytical and problem-solving skills, excellent communication, and leadership potential.
While academic performance matters, BCG also values personal drive, curiosity, and candidates who have made a real impact in their past experiences. The firm puts a strong emphasis on diversity and inclusion and actively seeks people from different backgrounds, academic fields, and perspectives.
Want to learn more about BCG? Check out these useful resources:
👉 BCG Case Interview
👉 BCG Online Case
👉 BCG Potential Test
The term “Big Four” refers to the four largest professional services firms in the world: PricewaterhouseCoopers (PwC), Ernst & Young (EY), KPMG (Klynveld Peat Marwick Goerdeler), and Deloitte. All of them have grown to be multi-billion-dollar firms that employ hundreds of thousands of people across the globe. According to their own financial statements of 2022, they have a combined total revenue of nearly 190 billion dollars.
In recent years all four of these firms have accelerated their diversification into other professional services including Risk Assurance, Tax, Legal, and Consulting. They are regarded as one of the most reputable graduate employers and have been the training ground for many business leaders.
All the Big Four have a significant global presence and serve clients across various industries. They are referred to as the Big Four as they are similar in revenue and workforce size and make up a major share of the global market for auditing, tax and advisory services.
PwC was formed in 1998 through the merger of two firms with roots going back to the 19th century: Coopers & Lybrand and Price Waterhouse. Since then, PwC has evolved far beyond accounting.
Today, it offers a full range of professional services – from legal and deal advisory to management consulting – and works on more transactions (M&A, financing, etc.) than any other firm globally. Audit work is no longer PwC’s main source of revenue. Instead, the firm has a rapidly growing consulting division and the world’s largest tax practice.
What Makes PwC Different?
PwC puts a big focus on technology and digital transformation. The firm has made important investments in areas like cybersecurity, data analytics, artificial intelligence, and cloud computing. PwC's deep expertise in these fields enables them to guide clients effectively through complex digital transformations and harness the potential of emerging technologies.
With over 370,000 employees worldwide, PwC serves clients in nearly every major industry and region. The firm’s mission is to “build trust in society and solve important problems,” which reflects its strong focus on public sector work and its long-standing relationships with some of the world’s largest companies.
👉 Want to learn more about PwC and how to get in? Check out our PwC Interview Guide for insights on the firm and its application process.
By revenue, Deloitte is the biggest of the Big 4 boasting top-line revenue figures of over $59 billion - they have the most audit clients in the UK’s FTSE 100. The firm offers a wide spectrum of professional services to its clients from risk assurance to strategy consulting. They often sponsor major sporting events and even sponsored the summer Olympics in 2012.
What Is Deloitte’s Purpose?
Deloitte’s purpose is clear: “Make an impact that matters.” The firm focuses on delivering real results, often through large-scale, multi-million-dollar projects with high-profile clients. It’s not just about developing strategies; it’s about putting them into action. That could mean helping businesses digitize their operations or supporting their expansion into new international markets.
What Does Deloitte’s Consulting Work Look Like?
Deloitte’s consulting practice goes beyond traditional strategy and operations. This includes assisting clients in expanding their operations internationally, navigating complex regulatory environments, managing cross-border transactions, and optimizing global supply chains.
A main focus is on emerging technologies. Deloitte is actively exploring areas like AI, robotics, and blockchain, helping clients understand how to use these innovations to drive sustainable growth and digital transformation. The firm runs its own innovation hubs and research teams and partners with leading tech companies to stay ahead of the curve and to make sure clients do, too.
Curious about Deloitte? Check out these resources to learn more:
👉 Deloitte Case Interview
👉 Career at Deloitte
EY was formed through a series of mergers between British and American accounting firms over the last century. The most important ones involved Whinney, Smith & Whinney (UK), Ernst & Ernst (US), and Arthur Young & Co. (US) – eventually becoming Ernst & Young.
In 1997, EY nearly merged with rival firm KPMG, but the deal fell through due to regulatory concerns, client pushback, and high costs. In 2013, the firm rebranded simply as EY and began expanding its consulting arm, including the acquisition of strategy firm Parthenon.
Today, EY’s U.S. business is particularly strong – it serves more S&P 500 companies than any of the other Big Four firms. In the UK, EY is on par with PwC in terms of market presence, although it has fewer clients than Deloitte.
What’s EY’s Purpose?
EY’s slogan is: “Building a better working world.” Beyond its core services in audit and tax, EY has become a major player in digital transformation, competing with firms like Accenture, Capgemini, and IBM. The firm was recently named a global leader in digital business transformation.
What Makes EY Stand Out?
EY is deeply connected to the global start-up ecosystem and works closely with incubators and accelerators. Through its well-known “EY Entrepreneur of the Year®” award, the firm shines a spotlight on innovative founders and growing businesses. Programs like the EY Start-up Challenge also offer workshops, mentoring, and networking to help start-ups build sustainable business models.
EY also leads the way in diversity and inclusion. The firm has ambitious goals, such as achieving gender parity in leadership and increasing representation of underrepresented groups across the organization. EY has received several awards for its efforts, including being named one of Forbes’ Best Companies for Diversity.
KPMG is the smallest of the Big Four in terms of revenue, but still a leading global firm. Today, the firm operates through a large network of member firms across more than 145 countries. It offers a wide range of professional services across audit, tax, and consulting, supporting clients across different industries and regions.
KPMG’s consulting work covers everything from classic management consulting to digital transformation, tech advisory, deal support, and risk consulting, making it a strong full-service provider across multiple disciplines.
What’s KPMG’s Purpose?
KPMG’s purpose is to ‘Inspire confidence and empower change. They see themselves as long-term partners with their clients across all areas of their business and KPMG want their employees to be proud of the work they do. They compete on all service fronts with the rest of the Big Four and the main contributing factor to their smaller size is a result of the other mergers and acquisitions that the other firms undertook rather than quality or reputation.
How Does KPMG Drive Innovation?
To stay ahead, KPMG has set up Insights Centers around the world – spaces where teams can work together, explore new technologies, and come up with innovative solutions for clients.
The firm also regularly publishes research reports, industry insights, and whitepapers, and has built a strong network of start-ups, academics, and tech partners to deliver the latest trends and ideas to its clients.
👉 Want to learn more about KPMG and how to apply? Check out our KPMG Interview Guide for all the details!
Even though MBB and the Big Four are often mentioned in the same breath, there are some key differences between them – from the types of projects they take on to their structure, reputation, and client focus. To help you get a quick overview, here’s a simple comparison:
| Criteria | MBB (McKinsey, BCG, Bain) | Big Four (PwC, Deloitte, EY, KPMG) |
| Focus | Pure strategy consulting | Audit, tax, and a broad range of consulting services |
| Projects | High-level strategic work at the C-suite level | Mix of strategy, implementation, and operational work |
| Clients | Large corporations, governments, and private equity firms | Wide range: from SMEs to global companies and the public sector |
| Organizational setup | Lean, specialized consulting organizations | Multidisciplinary matrix structure with multiple service lines |
| Consulting share | 100% focused on consulting | Consulting is one part of a larger business that includes audit & tax |
| Reputation | Highly exclusive, seen as strategic elite | Strongly established, but more broadly positioned |
| Career profile | Steep learning curve, fast-paced, strong career accelerator | Broader skill set, often better work-life balance |
MBB and the Big Four both play major roles in the consulting world, but with very different focuses. MBB stands for deep, high-impact strategy work, usually in close collaboration with top executives. The Big Four, on the other hand, offer a much broader range of services, including audit, tax, tech, and advisory, with more variety in project types and client profiles.
Which path is right for you depends on what you’re looking for:
If you want deep strategic work and a fast career boost, MBB might be your ideal fit.
If you prefer a broader perspective, more flexibility, and a potentially better work-life balance, the Big Four could be a great choice.
While the Big Three and the Big Four consulting firms have their distinct characteristics, there are also several similarities that can be observed:
1. Global Presence
Both the Big Three and the Big Four have a strong global presence with offices in multiple countries. They operate on a global scale and serve clients across various regions and industries.
2. Partnership Model
Both groups operate as partnerships. That means partners act like business owners – they bring in clients, take on leadership responsibilities, and share directly in the firm's financial success.
3. Consulting Services
Whilst there has been some level of competition between the Big 3 and Big 4 for over 20 years, it was when EY, Deloitte, and PwC all acquired strategy consulting firms (some of the Big 3’s competitors) that they began to offer the same services and compete more often for work.
4. Focus on Top Talent
Both MBB and the Big Four actively recruit ambitious, high-performing students, often from top universities. They look for people with strong analytical skills, leadership potential, and problem-solving ability, regardless of academic background.
5. Team and Knowledge Culture
Whether it’s MBB or the Big Four, teamwork and knowledge sharing are core to how these firms operate. Most projects are cross-functional, and collaboration across different teams and disciplines is a key part of the job.
6. Client Focus
Both groups work closely with clients to develop tailored solutions. They take time to truly understand their clients’ business models, markets, and challenges – and use that knowledge to deliver targeted, impactful recommendations.
Getting a job offer from MBB or the Big Four is a major achievement either way – both have tough and highly competitive recruiting processes. But many candidates eventually ask themselves: Which environment is the better fit for my career goals?
In reality, that decision is often shaped by the application process itself. While the Big Four consider a broader pool of applicants, MBB sets the bar extremely high and only invites a small percentage of candidates to interviews.
The Big Four typically look for qualified, motivated students with solid grades and some relevant experience – like internships, working student roles, or time abroad. Many entry-level hires come in through structured graduate programs, which are especially accessible for Bachelor’s graduates.
MBB, on the other hand, has a more selective approach. They’re looking for top academic performance (usually from highly ranked target universities), strong analytical thinking, an entrepreneurial mindset, and ideally, internships at prestigious companies. The interview process is known to be more demanding, especially the case interviews, which are often more complex and fast-paced.
Salary differences are especially noticeable at the entry level. MBB firms generally offer higher base salaries and total compensation, reflecting their focus on high-level strategy work and their highly selective hiring process.
Here’s a comparison of typical starting salaries in the U.S.:
| Firm | Base Salary | Performance Bonus | Total Compensation |
| McKinsey | $112,000 | up to $18,000 | up to $130,000+ |
| BCG | $110,000 | up to $22,000 | up to $132,000+ |
| Bain | $112,000 | up to $22,500 | up to $134,500+ |
| Deloitte | $88,000–$97,500 | up to $26,250 | up to $114,250+ |
| EY | $85,000–$100,000 | real-time bonuses | up to $85,000+ |
| KPMG | $78,000–$90,000 | up to $15,000 | up to $92,000+ |
| PwC | $85,000 | up to $7,500 | up to $87,500+ |
As the table shows, McKinsey, BCG, and Bain (MBB) offer the highest base salaries and overall compensation packages for entry-level roles, with Bain coming out slightly ahead on bonus potential. Deloitte offers a competitive performance bonus, but its base salary is lower than MBB, placing its total compensation a bit behind. EY, KPMG, and PwC follow with more variation depending on the specific role and location, with PwC offering the lowest total compensation on average.
But salary isn’t everything. MBB usually offers faster promotion tracks, high-prestige projects, and strong exit opportunities – but also expects a high level of performance and time commitment. The Big Four, on the other hand, offer more variety in service areas (audit, tax, tech, etc.) and are often more accessible for Bachelor’s grads or those looking for more specialized roles.
In the end, the right choice depends on your career goals, interests, and preferred work environment, not just the paycheck.
👉 For more details, check out our article: Consulting Salaries in the United States.
The work environment at the Big Three firms is often described as fast-paced, intense, and highly demanding. The strategic nature of their projects and close collaboration with high-profile clients frequently result in long working days and extensive travel. On average, MBB consultants work between 60 and 70 hours per week, sometimes even more depending on the project phase and client pressure.
The Big Four consulting firms, while also demanding, tend to offer a more balanced work environment. This is mainly due to their broader range of service lines (such as Audit, Tax, and Advisory) and the variety of project types. On average, consultants at the Big Four typically work around 45 to 55 hours per week, though hours can increase significantly during busy periods like project deadlines or audit season.
👉 Want to dive deeper? Check out our article on Work-Life Balance in Consulting.
Starting a career at either MBB or the Big Four is a strong move, just getting in is already a big accomplishment. But what happens next?
Working at MBB is often seen as a stepping stone to leadership positions. Many alumni go on to become C-level execs, join corporate strategy teams at former clients, or transition into private equity or venture capital. Starting your own business is also a common next step, thanks to the strategic mindset and problem-solving skills you develop at MBB.
The Big Four may be less exclusive, but they offer solid, long-term career paths – especially in areas like mid-sized companies, start-ups, or internal roles within the firm. You’ll find opportunities in strategy, HR, marketing, IT, and more, often with more predictable career progression and a healthier work-life balance than in purely client-facing roles.
Both groups also offer strong international mobility and cross-functional learning – so whether you’re focused on climbing the ladder fast or exploring a broad range of interests, you’ll find room to grow.
👉 Check out our full guide to Consulting Career Paths for everything you need to know about roles, salary, and advancement.
MBB (McKinsey, BCG, Bain) and the Big Four (PwC, Deloitte, EY, KPMG) are some of the most well-known names in the consulting world – and top targets for many aspiring consultants. While MBB focuses purely on high-level strategy consulting for top management, the Big Four offer a broader range of services, including audit, tax, technology, and implementation work.
Choosing between the two depends largely on your personal goals:
If you’re aiming for steep learning curves, deep strategic work, and exclusive career opportunities, MBB might be the better fit. If you want to explore different areas, build a more versatile skill set, or prefer a more balanced work-life setup in the long run, the Big Four offer great options.
What both groups have in common is their high bar for analytical thinking, teamwork, and an entrepreneurial mindset – as well as their global presence and close collaboration with clients.
No matter which path you choose, both can open doors and lay the foundation for a successful career in consulting.
