Board Thread:Support Requests - Community Management/@comment-4957813-20140707034838/@comment-452-20140707131017

This is my favourite one: https://tools.wmflabs.org/blockcalc/

You just paste in all the IP addresses he has used, and it will give you the range to block. But as UltimateSupreme said, be sure to keep your range blocks as narrow as necessary.

(It was offline for a little while, I only just noticed it's back.)