tools ▸ raid calculator

Usable storage,any RAID level.

Choose a RAID level, number of disks and disk size to see usable capacity, how many drives can fail and the performance trade-off.

RAID level

Number of disks

Disk size

Unit

Span groups (RAID 50/60)

result—

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raid calculator ▸ explained

What you need
to know.

Calculate usable capacity, fault tolerance and efficiency for RAID 0, 1, 5, 6, 10, 50 and 60.

RAID 1 / 10

Half your raw capacity, best write performance and fast rebuilds — the default for databases.

RAID 5 / 6

More usable space; RAID 6 survives two failures, which matters with large, slow-rebuilding disks.

backup

RAID protects against disk failure, not deletion, ransomware or corruption.

related ▸ more free tools

faq ▸ before you buy

Which RAID is best for a dedicated server?+

RAID 10 on NVMe or SSD for databases and busy sites; RAID 6 for large capacity storage where write speed matters less.

How much usable space does RAID 5 give?+

(Number of disks − 1) × smallest disk size. Four 4 TB disks give 12 TB usable.

Is RAID a backup?+

No. Deletions and corruption are mirrored instantly. Always keep separate, versioned backups.

~$ provision --region in ✓ done in 47s