RAID capacity calculator

Usable capacity and fault tolerance for RAID 0/1/5/6/10 from drive count and size.

Same disks across RAID 0 / 1 / 5 / 6 / 10 — usable capacity, efficiency, and fault tolerance side by side.

Equal-sized disks assumed — arrays use the smallest member. RAID 1 keeps a full copy on every drive (capacity of one, survives N−1 failures). RAID is not backup.

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How to use

  1. Pick the RAID level.
  2. Enter drive count and per-drive size.
  3. Read usable capacity, redundancy, and overhead.

What it supports

RAID 0/1/5/6/10 with identical drives — min counts 2/2/3/4/4, RAID 1 mirrors every drive (capacity = one drive), RAID 10 needs an even count, up to 64 drives; per-drive size in decimal TB up to 10^6.

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