The subscribed kVA is often a rack’s true limiting factor, before U height. Orders of magnitude: a rack of standard servers draws 2 to 4 kVA; a dense rack (virtualization, storage) 6 to 10 kVA; HPC or AI can exceed 20 kVA and requires adapted rooms (or liquid cooling).
Reliable method: add the real consumption of each machine (≈300 W for a standard 1U server, 800 W+ under load) then add 25% for peaks and power factor. Across our catalog, power is billed 150–260 €/kVA/month; check whether it is bundled in the rack rent or metered separately, and whether feeds are redundant (A+B).