That is too generic of a question. It greatly depends how active the users are. It is a combination of total bandwidth as well as the number of open sessions each user has. If you have a large enough internet connection many of the better consumer router will have no issues even with 100 users. It is mostly a function of memory and cpu capacity and these have gotten very large.
Now if you mean wireless that is more a function of how wireless works and how badly it shares the radio bandwidth. You are massively over the number of users. 30 is a maximum you see recommended and the recommended number if 7-10 for moderate usage and even less for usage like video streaming.