According to revenue figures from 2017, Deloitte was the biggest of the four companies, with around 38.8 billion U.S. dollars in revenue for that year. PricewaterhouseCoopers (PwC) also generated almost 37.7 billion U.S. dollars in revenue in 2017. Ernst & Young and KPMG, also high rollers in the industry, generated 31.4 and 26.4 billion U.S. dollars in revenue respectively. The Big Four generate the largest share of their revenue through their audit/assurance branches.
Each of these four firms employs more than 190,000 people a piece. Deloitte has the most employees at approximately 263,900 and KPMG has the fewest with around 197,000 employees.