Calculate the number of communication channels in your team using the n(n-1)/2 formula. Essential for PMP stakeholder management questions.
Communication Channels
45
n(n-1)/2 = 10×9/2 = 45
+1 person
55 channels (+10 new)
-1 person
36 channels (-9 fewer)
| Team Size | Channels | Delta |
|---|---|---|
| 2 | 1 | +1 |
| 3 | 3 | +2 |
| 5 | 10 | +4 |
| 8 | 28 | +7 |
| 10(current) | 45 | +9 |
| 15 | 105 | +14 |
| 20 | 190 | +19 |
| 25 | 300 | +24 |
| 30 | 435 | +29 |
| 50 | 1,225 | +49 |
n(n - 1) / 2Where n = total number of people (including the project manager)This formula calculates the total number of unique, two-way communication paths in a group. Each person can communicate with every other person, and each pair is counted only once.
Communication channels grow exponentially, not linearly. Adding one person to a team of 10 creates 10 new channels (from 45 to 55). Adding one person to a team of 50 creates 50 new channels (from 1,225 to 1,275). This is why large teams experience communication breakdowns and why project managers need structured communication plans.
n(n − 1) / 2, where n is the total number of people on the project — including the project manager. The result is the number of unique two-way communication paths in the team.
Each pair of people forms a single shared channel, not two separate channels. Dividing n(n − 1) by 2 removes the duplicate (A↔B is the same channel as B↔A).
Yes. Count every participant who communicates on the project, including yourself. PMP exam questions assume the PM is part of n unless explicitly told otherwise.
Usually one or two People-domain questions on calculating channels after team growth, or on the communication overhead created by adding stakeholders.