There's no single answer to how many years of college a top executive needs. While a bachelor's degree (4 years) is increasingly common and often a minimum requirement for many executive positions, many top executives have MBAs (Master of Business Administration, typically requiring an additional 2 years of study beyond a bachelor's degree). Some may even have other advanced degrees.
However, it's crucial to understand that a college degree is not always a *requirement* for reaching the highest executive levels. Many successful executives have risen through the ranks based on experience, skills, and demonstrable success, even without a formal college education. The importance of formal education varies significantly depending on the industry and specific company.