Raidcapacity Calculator
Our storage & raid tool computes raidcapacity accurately. Enter your inputs for detailed analysis and optimization tips.
Reviewed by Daniel Agrici, Founder & Lead Developer
Formula
Usable = (N - P) x Disk Size
Where N is the number of disks, P is the number of parity/mirror disks (varies by RAID level), and Disk Size is the capacity of each individual drive. RAID 0: P=0, RAID 1: P=N-1, RAID 5: P=1, RAID 6: P=2, RAID 10: P=N/2.
Worked Examples
Example 1: NAS with RAID 5
Problem:You have 4 x 4TB drives configured in RAID 5. Calculate usable capacity and storage efficiency.
Solution:Total raw capacity: 4 x 4,000 GB = 16,000 GB\nRAID 5 usable: (n-1) x disk size = 3 x 4,000 = 12,000 GB\nParity overhead: 1 x 4,000 = 4,000 GB\nStorage efficiency: 12,000 / 16,000 = 75%\nFault tolerance: 1 disk failure
Result:Usable: 12,000 GB (12 TB) | Efficiency: 75% | Fault tolerance: 1 disk
Example 2: Database Server with RAID 10
Problem:A database server uses 6 x 2TB SSDs in RAID 10. Calculate usable capacity and performance characteristics.
Solution:Total raw capacity: 6 x 2,000 GB = 12,000 GB\nRAID 10 usable: (n/2) x disk size = 3 x 2,000 = 6,000 GB\nMirror overhead: 6,000 GB\nStorage efficiency: 6,000 / 12,000 = 50%\nRead performance: 6x single disk\nWrite performance: 3x single disk
Result:Usable: 6,000 GB (6 TB) | Efficiency: 50% | Read: 6x, Write: 3x single disk speed
References
Reviewed by Daniel Agrici, Founder & Lead Developer · Editorial policy