Enterprise ZFS NAS Capacity Calculator

ZFS RAID-Z capacity is calculated differently from normal RAID levels. Before implementing Enterprise ZFS NAS, use this calculator to estimate the total usable storage capacity and the number of drives you need.


  1. As QES takes up storage space (13GB per system drive, totally 4 system drives), the actual usable storage capacity will be less than the calculated result.
  2. This calculator assumes that the capacity of drives and RAID groups are identical.
  3. This calculator excludes spare drives. Please arrange additional spare drives to ensure reliability.
  4. Different RAID-Z types use a different number of hard drives.
  5. A RAID 5/6 configuration is required before creating a RAID 50/60 group.
  6. This calculator only applies to QNAP Enterprise ZFS NAS.
  7. This calculator is intended for estimation purposes only. Actual usable storage capacity is still based on the result that QES Storage Manager shows.