Enterprises by business size is the categorisation of businesses by number of people employed.

An enterprise is defined as a legal entity possessing the right to conduct business on its own, for example to enter into contracts, own property, incur liabilities and establish bank accounts. An enterprise may be a corporation, a quasi- corporation, a non-profit institution, or an unincorporated enterprise.

Enterprises can be classified in different categories according to their size; for this purpose, different criteria may be used, but the most common is number of people employed. In small and medium-sized enterprises (SMEs) employ fewer than 250 people. SMEs are further subdivided into micro enterprises (fewer than 10 employees), small enterprises (10 to 49 employees), medium-sized enterprises (50 to 249 employees). Large enterprises employ 250 or more people.

This indicator is measured as the number of employees in the manufacturing sector.