Technology & Computing
RAID Usable Storage & Parity Overhead Calculator
Calculate usable capacity and parity overhead for RAID 0, 1, 5, 6, 10, 50 and 60 arrays.
Your inputs
Change any value to update the result instantly.
Usable storage capacity
28 TB
Raw total capacity
32 TB
Overhead (parity/mirroring)
12.5%
Drives worth of usable data
7
Actual usable capacity is set by the smallest drive in the array multiplied by the drive count — mixing drive sizes wastes the extra capacity of larger drives.
Formula and working
Usable capacity depends on RAID level: RAID0 = n×d; RAID1 = d; RAID5 = (n−1)×d; RAID6 = (n−2)×d; RAID10 = (n/2)×d
- 1
Collect the inputs
Number of drives = 8; Drive capacity (TB) = 4; RAID level = 5
- 2
Apply the formula
Usable capacity depends on RAID level: RAID0 = n×d; RAID1 = d; RAID5 = (n−1)×d; RAID6 = (n−2)×d; RAID10 = (n/2)×d
- 3
Result
Usable storage capacity = 28 TB
Frequently asked questions
Important limitation
This is an educational estimate based only on the values and formula shown. Verify current rates, rules, units, and professional standards before relying on the result. It is not personalized financial or investment advice.
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