- Small: < 100 employees

- Mid-sized: 100 - 1,500/2,000 employees.

- Large: > 1,500/2,000 employees.

See: <https://www.indeed.com/career-advice/career-development/busi...> <https://learn.g2.com/business-size>.

The US Bureau of Labour Statistics identifies nine classes of businesses for employment dynamics, the largest being 1,000 employees: <https://www.bls.gov/bdm/bdmfirmsize.htm>.

I'm surprised by the latter as there are many companies with > 10k employees.

The list of 100 largest US companies by headcount ends with Meta at 78,865 employees. The top ten have 309,000 or more employees, two (Walmart and Amazon) over 1 million. The top 5 are all retail, delivery, or both (Amazon).

<https://stockanalysis.com/list/most-employees/>