ganak.appRAID Calculator
Calculate RAID array capacity, storage efficiency, fault tolerance, and performance for RAID 0, 1, 5, 6, 10, 50, and 60. Compare RAID levels side-by-side with cost-per-TB analysis. Supports hot spares, filesystem overhead, and drive type speed estimates.
Storage Breakdown
How your storage is allocated
RAID Level Comparison
All RAID levels with your current 4× 4 TB configuration
| Level | Usable | Eff. | Tolerance | Read | Write |
|---|---|---|---|---|---|
| JBOD | 16.0 TB | 100% | 0 | 1× | 1× |
| RAID 0 | 16.0 TB | 100% | 0 | 4× | 4× |
| RAID 1 | 4.0 TB | 25% | 3 | 4× | 1× |
| RAID 5 | 12.0 TB | 75% | 1 | 3× | 3× |
| RAID 6 | 8.0 TB | 50% | 2 | 2× | 2× |
| RAID 10 | 8.0 TB | 50% | 1 | 4× | 2× |
| RAID 50 | — | — | — | — | — |
| RAID 60 | — | — | — | — | — |
* Speed multipliers are theoretical maximums relative to a single drive. Real-world performance depends on controller, drive type, and workload.
How RAID Capacity Is Calculated
Understanding storage formulas for each RAID level
RAID (Redundant Array of Independent Disks) combines multiple drives into a single logical unit. The usable capacity depends on the RAID level chosen, as each level allocates storage differently between data and redundancy.
| Level | Formula | Min Disks | Method |
|---|---|---|---|
| JBOD | N × D | 1 | Concatenation |
| RAID 0 | N × D | 2 | Striping |
| RAID 1 | D | 2 | Mirroring |
| RAID 5 | (N-1) × D | 3 | Striping + Parity |
| RAID 6 | (N-2) × D | 4 | Striping + 2× Parity |
| RAID 10 | (N/2) × D | 4 | Mirror + Stripe |
| RAID 50 | G×((N/G)-1)×D | 6 | RAID 5 groups, striped |
| RAID 60 | G×((N/G)-2)×D | 8 | RAID 6 groups, striped |
Where N = number of drives, D = individual drive capacity, G = number of RAID groups. After applying the RAID formula, subtract ~7% for filesystem formatting overhead.
RAID Levels Explained
Pros, cons, and ideal use cases for each level
RAID 0
StripingRAID 1
MirroringRAID 5
Striping + Distributed ParityRAID 6
Striping + Double ParityRAID 10
Mirroring + StripingWhen to Use Each RAID Level
Real-world scenarios and recommendations
NAS / Home Media Server
RAID 5 for small NAS (3-5 drives) or RAID 6 for larger arrays. Balances capacity with single/double drive fault tolerance. Good for Plex, file storage, and backups.
Enterprise Database
RAID 10 for databases needing fast random I/O. The mirroring provides excellent read performance while maintaining write speed. Best for SQL Server, PostgreSQL, or MongoDB.
Video Editing / Production
RAID 0 for scratch drives where speed is critical and data is backed up elsewhere. RAID 5/6 for project storage that needs protection. Large sequential transfers benefit from high stripe counts.
Large-Scale Storage / Archiving
RAID 60 for large arrays (12+ drives). Provides dual parity per group, tolerating multiple simultaneous drive failures. Ideal for backup targets, cold storage, and compliance archives.
Common RAID Mistakes to Avoid
Frequent errors when planning a RAID array
Treating RAID as a backup
RAID protects against drive failure, not against accidental deletion, ransomware, fire, or controller failure. Always maintain separate backups — RAID is not a backup strategy.
Mixing different drive sizes
In a RAID array, all drives are treated as the size of the smallest drive. A 4TB + 8TB RAID 1 array only provides 4TB of usable storage. Always use identical drives.
Ignoring rebuild times on large arrays
With 8TB+ drives, a RAID 5 rebuild can take 12-24+ hours. During rebuild, a second drive failure means total data loss. For large drives, prefer RAID 6 or RAID 10.
Choosing RAID 0 without understanding the risk
RAID 0 has zero fault tolerance — any single drive failure destroys all data across every drive. Only use RAID 0 for temporary data, scratch disks, or when data is fully backed up elsewhere.
Frequently Asked Questions
Common questions about RAID configurations and capacity