Docker Container capacity planning I'm running my application on 4 Virtual Machines with 8 3.2 GHz Virtual CPUs and 32 GB, however, I will be splitting up the processes into separate containers.

I am not sure how many containers to run per host. What are the typical numbers?
 For example how the VM to bare metal server ratio is 1:10 generally, any links on attributes to consider, decision frameworks to consider or experiences would help!
The same as any Linux load, consider no more processes in wait state than the number of CPU.
The load on 1, 5 and 15 mins given by uptime should ideally be 1 less than number of cores. 

Containers are roughly isolated processes, leaving a core for orchestration avoid congestion. 

That doesn't mean only 7 containers on a 8 cores machine, it's a matter of simultaneous load, so the best way is to measure it and adapt consequently.