Metcalfe’s Law

One-Sentence Definition

The value of a network is proportional to the square of the number of its users—the more users, the greater the value.

Core Concept

Metcalfe’s Law: The value of a network equals the square of the number of users. A network of 10 people has a value of 100, while a network of 100 people has a value of 10,000. This explains the network effect of social networks.

What Problem Does It Solve

When information is incomplete, options are numerous, or risks are unclear, it helps pull your judgment from intuition back to structured analysis.

More specifically, Metcalfe’s Law is suitable for answering questions like: How can I better understand the current situation? How can I make more reasonable judgments and take action?

When to Use

• When problems become complex and intuitive judgment is no longer reliable.
• When the team disagrees on the next steps and needs a shared analytical framework.
• When you need to translate abstract judgments into concrete actions, checklists, or experiments.
• When existing practices are losing effectiveness and the underlying logic needs re-examination.

When Not to Use

• The problem is simple, and direct execution is more important than analysis.
• Basic facts are lacking, and you are merely spinning concepts.
• The model is used only to justify existing conclusions rather than to help refine judgment.

Summary

Metcalfe’s Law explains why platform-based products pursue user scale—scale itself is value.