In the UK we use middle class to mean something much closer to its Marxist definition. Doctors, lawyers, engineers, managers, and small business owners would generally be considered middle class (basically if you can afford to shop at M&S or Waitrose). The term middle class in the UK also can encompass people who should be included in the term upper/ruling class, such as CEOs, but due to our weird historic class system in the UK I think there is a higher threshold for being considered upper class here.