It really depends on whether you mean _reservable_ or _usable_ capacity. Reservable capacity is what you are doing minus what ESXi is reserving. Usable capacity is what you are doing plus max all core turbo boost cycles, plus SMT/HT capacity, minus the small but variable amount ESXi non-VM worlds are consuming. I tried to explain it in the 2nd part here: https://via.vmw.com/MCL1635