Use our free RAID Array Storage Capacity & Rebuild Time Calculator to quickly determine your usable storage space and estimate how long it will take to rebuild your array after a drive failure. This tool is perfect for IT professionals, system administrators, and DIY enthusiasts planning or managing their data storage solutions. Optimize your server or NAS setup by understanding your actual capacity and potential recovery times.
Formula:
Usable Capacity: The total storage space available after accounting for redundancy. Depends on RAID level and number/size of disks.
- RAID 0:
N × Disk Size(Striping, no redundancy) - RAID 1:
1 × Disk Size(Mirroring, for N≥2 disks) - RAID 5:
(N-1) × Disk Size(Striping with parity, for N≥3 disks) - RAID 6:
(N-2) × Disk Size(Striping with dual parity, for N≥4 disks) - RAID 10 (1+0):
(N/2) × Disk Size(Striping & mirroring, for N≥4, N must be even)
Rebuild Time: Estimated time to reconstruct data onto a replacement drive after a single disk failure.
Rebuild Time = (Failed Disk Size / Rebuild Speed)
Where:
- N: Number of disks in the array
- Disk Size: Individual disk capacity
- Rebuild Speed: Estimated data transfer rate during rebuild (e.g., MB/s or GB/hr)