RAID Capacity Calculator
Usable, raw, and parity capacity for RAID 0/1/5/6/10/50/60. Fault tolerance and efficiency.
published
- [FREE]
- [NO_SIGNUP]
- [NO_UPLOAD]
A RAID capacity calculator computes usable storage for the seven common RAID configurations.
Privacy
Pure JS. No upload.
Frequently asked questions
Which RAID level should I pick?
For 2 drives: RAID 1 (mirror, survives 1 failure). For 3-5 drives: RAID 5 (one parity, balanced). For 4+ drives with high uptime: RAID 6 (two parity, survives 2 failures). For performance + redundancy: RAID 10 (loses half capacity). For very large arrays (10+ drives): RAID 60.
Is RAID a backup?
No. RAID protects against drive failure. It does not protect against ransomware, accidental delete, or fire / theft. Always run a separate backup.
What about RAID 5 with large modern drives?
Rebuild times on multi-TB drives stretch into days. During rebuild a second drive failure or unrecoverable read error becomes likely. For drives ≥ 4 TB, RAID 6 or RAID 10 is generally preferred.