Host Specifications
RAM reserved by the hypervisor (e.g. VMware ESXi, Hyper-V)
Virtual CPUs per physical core (4:1 is common)
1.0 = no overcommit; 1.2 = 20% overcommit
VM Profile
About this tool
VM density planning is a balance between CPU and RAM constraints. vCPU overcommit (virtual CPUs per physical core) is well-established because VMs rarely use their allocation simultaneously, ratios of 4:1 to 8:1 are typical for general workloads, but CPU-intensive VMs (databases, compilation) may need 1:1 or 2:1. RAM overcommit is riskier: exceeding physical RAM triggers ballooning, swapping or page sharing, which can severely degrade performance. A ratio of 1.0 (no overcommit) is safest for production; 1.2–1.3 is acceptable for dev/test. Always reserve capacity for at least N-1 host failures in an HA cluster, the total VM count the tool shows should fit across N-1 hosts at normal utilisation.