Proxmox Storage Calculator
Size the raw storage your Proxmox VMs need — factor in per-VM disks, overhead and redundancy.
How much storage do your VMs need?
Sizing storage for a Proxmox host or cluster means more than adding up virtual disks. You also account for per-VM overhead (swap, logs, snapshots), and for the redundancy your storage layer adds — a mirror doubles raw usage, while parity RAID adds a smaller factor. This calculator combines those into a raw-capacity estimate.
The formula
Raw storage ≈ (number of VMs × (disk per VM + overhead)) × redundancy factor ÷ thin-provisioning ratio. Thin provisioning lets allocated disk exceed what is actually written, so a ratio above 1 reduces the raw capacity you need to buy — at the cost of watching real usage carefully.
Plan for growth
Add headroom on top of the result. Snapshots, backups staged locally, and future VMs all consume space, so many operators target 20–30% free capacity at all times.
Frequently asked questions
Does this include RAID overhead?
Yes. Choose your redundancy (mirror, parity or none) and the calculator applies the appropriate raw-capacity factor.
What is thin provisioning?
Thin provisioning allocates disk on demand, so total allocated size can exceed physical capacity. Set a ratio above 1 to model it — and monitor real usage.
Related
Stop sizing spreadsheets — automate it
Vormox provisions, sizes and manages VMs across your Proxmox nodes automatically. Connect your cluster to get started, or book a live demo.
Get StartedVormox is an independent virtualization management platform built on Proxmox VE. Proxmox® and Proxmox VE® are trademarks of Proxmox Server Solutions GmbH. Vormox is not affiliated with, endorsed by, or sponsored by Proxmox.