What is the federal definition of small business?

EU Member States traditionally had their own definition of what constitutes an SME, for example the traditional definition in Germany had a limit of 500 employees, while ,for example, in Belgium it could have been 100. But nowadays the EU has started to standardise the concept. Its current definition categorises companies with fewer than 50 employees as "small", and those with fewer than 250 as "medium". By contrast, in the United States, when small business is defined by the number of employees, it often refers to those with less than 100 employees, while medium-sized business often refers to those with less than 500 employees. However, the most widely used American definition of micro-business by the number of employees are the same of that of European Union: less than 10 employees.