While it's impossible to get an accurate user count across the fediverse due to several factors like spam signups, downtime and inflated metrics, it is possible to filter out inaccurate results using std dev and other metrics.
https://fedidb.org aims to be the most accurate source of fediverse network statistics and data, and I think we're on the right path! #fediDB
@dansup@mastodon.social Calckey isn't big enough to show up on the list. Unless it gets counted in with Misskey. Oh well, I like it