The standard English spelling is chaos.

Quick Scoop

  • The word chaos is spelled: c-h-a-o-s.
  • It’s a noun that means “a state of extreme confusion and disorder.”
  • Pronunciation in English is typically like “KAY-oss” (UK: /ˈkeɪ.ɒs/, US: /ˈkeɪ.ɑːs/).

Mini example

After the storm, the classroom was in chaos.

TL;DR: You spell it chaos.