How does K-Means behave when features have different units and scales?

Updated May 16, 2026

Short answer

Features with larger numeric scales dominate distance calculations, skewing clustering results.

Deep explanation

K-Means relies on Euclidean distance, so variables like income (0–100000) overpower variables like age (0–100). This leads to centroids being influenced primarily by high-magnitude features unless normalization is applied.

Real-world example

Clustering users where salary dominates behavioral metrics.

Common mistakes

  • Skipping normalization step.

Follow-up questions

  • What scaling is best?
  • Can scaling change cluster structure?

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