How many player slots should I have?
On average, most servers will be able to host roughly 20 players for every 1GB of RAM. However, the actual amount of players your server can run will depend on the number of plugins you're using, the size and amount of worlds as well as any other modifications you have made, the amount of player slots we assign to the machine is the recommended slots for that machine but again this is depending on the plugins or mods you use.
We don't suggest raising the limit beyond our recommendations as it could cause a server crash if too many players are on the server at once. However, it can be useful if you are very experienced and understand how to optimize your server for your specific use case.