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NAS / RAID Calculator
Calculate usable capacity, fault tolerance, and cost per TB for any RAID or ZFS configuration.
2TB500TB
$200$10,000
ZFS — 1 drive failure
ZFS RAIDZ1 Layout
Drives needed
3
Drive size
20TB
Usable capacity
40TB
Raw capacity
60TB
Overhead
33%
Fault tolerance
1 drive
Estimated cost
$657
Cost per TB
$16.43/TB
Recommended drive
Seagate Exos 20TB
CMR 7200rpm · 5yr warranty · $10.95/TB
$219 eachBuy →
RAID protects against drive failure, not ransomware or accidental deletion. Always maintain offsite backups.
FAQ
What RAID levels are supported?
RAID 1, 5, 6, and ZFS RAIDZ1/RAIDZ2/RAIDZ3. We recommend ZFS RAIDZ1 or RAIDZ2 for new builds.
Does RAID replace backups?
No. RAID protects against drive failure, not accidental deletion, ransomware, or site-level disasters. Always maintain offsite backups.
Which RAID level should I choose?
RAIDZ1 for home NAS with 3-6 drives. RAIDZ2 for larger arrays or critical data. RAID 6 for compatibility with non-ZFS systems.