RAID Calculator
Calculate usable storage capacity for different RAID configurations. Understand how RAID levels affect storage efficiency and redundancy.
How to Use This Calculator
- Select the RAID level (RAID 0, 1, 5, 6, or 10).
- Enter the number of drives in your RAID array.
- Enter the capacity of each drive in gigabytes.
- The calculator displays usable capacity, total capacity, storage efficiency, and redundancy status.
RAID Capacity Formulas
Usable capacity depends on RAID level:
RAID 1: Capacity = Drive Size (mirroring, 50% efficiency)
RAID 5: Capacity = (n - 1) × Drive Size (1 drive for parity)
RAID 6: Capacity = (n - 2) × Drive Size (2 drives for parity)
RAID 10: Capacity = (n / 2) × Drive Size (mirrored pairs)
Example: 4 drives × 1TB each: RAID 0 = 4TB (100% efficiency), RAID 1 = 1TB (25% efficiency), RAID 5 = 3TB (75% efficiency), RAID 6 = 2TB (50% efficiency), RAID 10 = 2TB (50% efficiency).
Full Description
RAID (Redundant Array of Independent Disks) is a storage technology that combines multiple physical drives into a single logical unit. Different RAID levels provide different trade-offs between storage capacity, performance, and fault tolerance. Understanding RAID capacity helps you plan storage systems, estimate usable space, and choose the right RAID level for your needs.
RAID 0 (striping) provides maximum capacity and performance but no redundancy—one drive failure loses all data. RAID 1 (mirroring) provides 100% redundancy but uses half the capacity. RAID 5 uses distributed parity, providing redundancy with better capacity efficiency than RAID 1. RAID 6 uses double parity for extra protection. RAID 10 combines mirroring and striping for the best of both worlds but requires an even number of drives.
This calculator helps you determine usable storage capacity for different RAID configurations. Select the RAID level, enter the number of drives and capacity, and it calculates usable capacity, total capacity, efficiency, and redundancy status. Use it when planning storage systems, comparing RAID levels, or understanding how RAID affects available storage. Choose RAID levels based on your priorities: performance, capacity, or redundancy.
Frequently Asked Questions
What is RAID?
RAID (Redundant Array of Independent Disks) combines multiple drives into a single logical unit for performance, redundancy, or both. Different RAID levels provide different trade-offs between capacity, performance, and fault tolerance.
What are the different RAID levels?
RAID 0: Striping (no redundancy, maximum performance). RAID 1: Mirroring (100% redundancy, half capacity). RAID 5: Striping with parity (1 drive redundancy, good performance). RAID 6: Striping with double parity (2 drive redundancy). RAID 10: Mirrored stripes (best of both).
Which RAID level should I use?
RAID 0: Maximum performance, no redundancy (use for non-critical data). RAID 1: Simple redundancy, good for 2 drives. RAID 5: Good balance, requires 3+ drives. RAID 6: Extra protection, requires 4+ drives. RAID 10: Best performance and redundancy, requires 4+ drives (even number).
What is storage efficiency?
Storage efficiency = (Usable capacity / Total capacity) × 100%. RAID 0: 100% (no redundancy). RAID 1: 50% (mirroring). RAID 5: (n-1)/n (one drive for parity). RAID 6: (n-2)/n (two drives for parity). RAID 10: 50% (mirroring).