Shota Aizawa (Eraser Head) is 30 years old at the start of My Hero Academia , and 31 in the later pre-timeskip parts of the story.

Aizawa’s Canon Age

  • Official character data lists Aizawa as 30 years old around his first major appearances as Class 1-A’s homeroom teacher.
  • As the story timeline moves forward before the big timeskip, his age is updated to 31 years old.

Extra Context Fans Discuss

  • Character profile resources and fan discussions consistently keep his birthday as November 8 and his height at 183 cm, matching the age range of 30–31 during the main school-era arcs.
  • Some forum threads extend the timeline further and note that, if you follow the in-universe years beyond the school festival and war arcs, Aizawa would be in his early 30s (often cited as 31) as events progress.

TL;DR: If you’re asking “how old is Aizawa” in the main My Hero Academia school-era story, the widely accepted answer is 30–31 years old.

Information gathered from public forums or data available on the internet and portrayed here.