States of the usa list for The North American Industry Classification System (NAICS) uses these size standards, and federal agencies are bound to apply them in procurement and contracting. The standards define the largest a firm may be, together with all of its affiliates, and still be considered a small business on an industry-by-industry basis; there is no general upper limit. Numerical definitions are almost always expressed in either the number of employees or average annual receipts (with the exception of industries such as power generation, where megawatt hours is used). The most widely used size standards are 500 employees for most manufacturing and mining industries, and $6 million in average annual receipts for most non-manufacturing industries. However, many exceptions exist. In much of farming, small businesses are limited to annual receipts of $0.75 million, in much of construction to $28. States of the usa list 2016.