how are the fortune 100 and fortune 500 different 
based on rankings from fortune magazine s fortune 500 list the fortune 100 are the 100 largest public and private companies in the united states based on revenues the fortune 100 is a subset of the fortune 500 derived from a list of companies that operate in the united states and report to federal agencies prior to 1994 the fortune 100 only included companies that operated in the mining manufacturing and energy sectors it has since included companies that operate in the services sector 