vSAN capacity planner
Usable space in a VMware vSAN cluster for a given host count, disks, protection policy and free-space reserve.
Capacity tier only: cache disks do not count.
VMware advises roughly 25 to 30 percent.
1 means none. Use a cautious figure if you enable deduplication or compression.
Runs in your browser. Nothing you type is sent to the server.
About this tool
Enter the number of hosts, the raw capacity each host contributes and the storage policy. The planner takes off the space kept free for rebuilds and growth, divides by the protection overhead of the policy (mirroring doubles the data, RAID-5 adds a third, RAID-6 adds half) and applies any space saving ratio you expect. It is an estimate for planning conversations; use VMware's own sizer for a purchase, because metadata, witness components and the vSAN architecture change the figures.