What Is Metcalfe's Law?

Date First Published: 31st May 2022

Topic: Computer Networking

Subtopic: Network Standards

Article Type: Computer Terms & Definitions

Difficulty Level: 5/10

Learn more about what Metcalfe's law is in this article.

Metcalfe’s law is a concept in computer networks that was created by Robert Metcalfe, the inventor of Ethernet and 3Com to represent the value of networks. It states that the value of a network is equivalent to the square of the number of nodes in the network. For example, if a network contained three computers and two printers, equal to five nodes, its value or impact would be 25 as 5² equals 25. If a network contained 800 nodes, its value or impact would be much higher. It would be 640,000 as 800² = 640,000.

Although Metcalfe’s law was first formulated by George Gilder in 1993, it was attributed to Robert Metcalfe in regard to Ethernet. Metcalfe’s law was originally presented in 1983 in a presentation to the 3Com sales force and indicated more about the value of compatible communicating devices, such as fax machines and telephones. For example, owning a single fax machine is useless. Having two fax machines will allow two people to communicate and having thousands of fax machines will increase the value of the devices. This is because the total number of people who each user may send and receive documents with adds up.

In a similar way, the more users using social networking services, the more valuable the service becomes to the community. Metcalfe’s law can include applications beyond the internet or networks. For example, a software program will increase in value as the number of users increases. If a a software program has only 10 users, it will be less known and used. But, if the software has thousands of users, it will be much more popular and well-known.

Limitations

Metcalfe’s law comes with some limitations. Metcalfe’s law assumes that the value of every node is of equal benefit. For example, if one fax machine serves 50 workers in an organisation, the second one serves 25, the third one serves a quarter, and so on, the value of additional connections drops.