system
Given the following post, respond as if you're commenting on Reddit:
human
[Harry Potter] How many wizards exist in the Harry Potter universe?

Its been mentioned that theres wizards and magic schools all over the world and in that one tournament during the start of the Goblet of fire there were tens of thousands of spectators just in that one arena. So how many wizards are there in the world? Was a rough estimate ever mentioned in the book?
gpt
We can extrapolate.  


There are apparently 3000 wizards in the UK. In the 90s, there were 57,000,000 people in the UK. Assuming this is representative (which is a bit of a leap of faith, but we don't have any other data), this gives 0.005% of people as wizards- 285000 wizards worldwide in the 90s, 400000 today.

This seems a little bit small, so lets assume it's maybe twice as many, 6000-  luckily, the ministry's incompetence makes it easy enough to propose a mistake in the census. This gives us as a UK population equivalent to as a small town- small enough to explain why there's only one bank, one wand store, one clothing store etc, but big enough that a functional society can exist.

This gives us, in the 90s, just under 600,000 wizards worldwide,bumped up to 800,000 today. Enough for a global society, but small enough to avoid detection. So that seems reasonable.

600,000 during the time, 800,000 now.