RAID Array Calculator
Choosing the right RAID configuration can significantly impact your storage performance, redundancy, and usable capacity. Whether you're building a NAS, configuring a server, or planning enterprise storage, understanding how different RAID levels affect usable space is critical.
Our RAID Array Calculator allows you to instantly calculate:
- RAID configuration details
- Total raw capacity
- Usable storage capacity
- Storage overhead
- Efficiency percentage
- Fault tolerance
With support for RAID 0, RAID 1, RAID 5, RAID 6, and RAID 10, this tool helps you make informed storage decisions in seconds.
What Is RAID?
RAID (Redundant Array of Independent Disks) is a method of combining multiple drives into a single logical storage unit to improve:
- Performance
- Data redundancy
- Fault tolerance
- Storage efficiency
Different RAID levels serve different purposes. Some prioritize speed, others focus on redundancy, and some offer a balance between both.
Our RAID Array Calculator simplifies the comparison process by instantly showing how each RAID type affects your storage.
Supported RAID Levels in This Calculator
The tool supports the following RAID configurations:
- RAID 0 (Striping)
- RAID 1 (Mirroring)
- RAID 5 (Striping with Parity)
- RAID 6 (Double Parity)
- RAID 10 (Mirrored Striping)
Each RAID type has unique characteristics, which we’ll explain below.
How to Use the RAID Array Calculator
Using the calculator is quick and straightforward.
Step 1: Select RAID Type
Choose from RAID 0, 1, 5, 6, or 10.
Step 2: Enter Number of Drives
Input the total number of drives in your array.
Note:
- RAID 0 requires minimum 2 drives
- RAID 1 requires minimum 2 drives
- RAID 5 requires minimum 3 drives
- RAID 6 requires minimum 4 drives
- RAID 10 requires minimum 4 drives (even number)
Step 3: Enter Drive Size (GB)
Enter the size of a single drive in gigabytes.
Step 4: Click Calculate
The calculator instantly displays:
- RAID configuration
- Total raw capacity
- Usable capacity
- Overhead
- Storage efficiency
- Fault tolerance
Step 5: Reset (Optional)
Use the reset button to start a new calculation.
How RAID Capacity Is Calculated
Here’s how each RAID level determines usable storage.
RAID 0 (Striping)
Minimum Drives: 2
Redundancy: None
Formula:
- Usable Capacity = Number of Drives × Drive Size
- Overhead = 0
- Efficiency = 100%
RAID 0 offers maximum performance and full storage efficiency but zero fault tolerance. If one drive fails, all data is lost.
Best for:
- Temporary data
- High-speed workloads
- Non-critical systems
RAID 1 (Mirroring)
Minimum Drives: 2
Redundancy: High
Formula:
- Usable Capacity = Size of One Drive
- Overhead = Total Raw − Usable
- Efficiency = 50% (with 2 drives)
RAID 1 mirrors data across drives. If one drive fails, the system continues running.
Best for:
- Critical systems
- OS drives
- Small servers
RAID 5 (Striping with Parity)
Minimum Drives: 3
Fault Tolerance: 1 Drive
Formula:
- Usable Capacity = (Drives − 1) × Drive Size
- Overhead = Size of One Drive
RAID 5 balances redundancy and efficiency.
Best for:
- Small business storage
- NAS devices
- File servers
RAID 6 (Double Parity)
Minimum Drives: 4
Fault Tolerance: 2 Drives
Formula:
- Usable Capacity = (Drives − 2) × Drive Size
- Overhead = 2 × Drive Size
RAID 6 provides extra protection by allowing two simultaneous drive failures.
Best for:
- Enterprise storage
- Large arrays
- Mission-critical data
RAID 10 (Mirrored Striping)
Minimum Drives: 4 (even number required)
Fault Tolerance: 1 drive per mirror pair
Formula:
- Usable Capacity = Total Raw ÷ 2
- Overhead = 50%
RAID 10 combines RAID 1 and RAID 0 for high performance and redundancy.
Best for:
- Databases
- Virtualization
- High-performance servers
Example RAID Calculations
Let’s explore some real-world scenarios.
Example 1: RAID 0
Drives: 4
Drive Size: 1000 GB
Total Raw: 4000 GB
Usable: 4000 GB
Efficiency: 100%
Fault Tolerance: None
Example 2: RAID 5
Drives: 4
Drive Size: 2000 GB
Total Raw: 8000 GB
Usable: 6000 GB
Overhead: 2000 GB
Efficiency: 75%
Fault Tolerance: 1 drive
Example 3: RAID 6
Drives: 6
Drive Size: 2000 GB
Total Raw: 12000 GB
Usable: 8000 GB
Overhead: 4000 GB
Efficiency: 66.67%
Fault Tolerance: 2 drives
Example 4: RAID 10
Drives: 4
Drive Size: 1000 GB
Total Raw: 4000 GB
Usable: 2000 GB
Overhead: 2000 GB
Efficiency: 50%
Fault Tolerance: 1 drive per mirror pair
Why Use This RAID Array Calculator?
Manual RAID calculations can be confusing, especially when comparing multiple RAID levels.
This tool helps you:
- Compare RAID types instantly
- Understand storage efficiency
- Plan hardware purchases
- Estimate redundancy levels
- Avoid configuration mistakes
- Optimize cost vs protection
It eliminates guesswork and simplifies storage planning.
Key Storage Planning Tips
- Always use identical drive sizes for best results.
- Larger arrays increase rebuild time.
- RAID is not a backup solution.
- Consider workload type before choosing RAID level.
- Balance efficiency with redundancy.
When to Choose Each RAID Level
Choose RAID 0 if:
- You need maximum speed
- Data is non-critical
Choose RAID 1 if:
- You need simple redundancy
- Capacity requirements are small
Choose RAID 5 if:
- You want balanced performance and efficiency
Choose RAID 6 if:
- You need higher fault tolerance
- You’re using large capacity drives
Choose RAID 10 if:
- Performance and redundancy are equally critical
15 Frequently Asked Questions (FAQs)
1. What is the best RAID level?
It depends on your needs. RAID 10 is often preferred for performance and redundancy.
2. Does RAID replace backup?
No. RAID protects against drive failure, not data loss.
3. Which RAID has the highest efficiency?
RAID 0 offers 100% efficiency but no redundancy.
4. How many drives do I need for RAID 5?
Minimum 3 drives.
5. How many drives are required for RAID 6?
Minimum 4 drives.
6. Why does RAID 10 require an even number of drives?
Because drives are paired into mirrors.
7. Can RAID 6 survive two drive failures?
Yes, it supports double parity.
8. Is RAID 0 safe?
No. It has zero fault tolerance.
9. Why does RAID 1 have low efficiency?
Because data is duplicated across drives.
10. Does this calculator support different drive sizes?
It assumes equal drive sizes for accurate calculation.
11. What is storage overhead?
Space used for redundancy instead of data.
12. What is fault tolerance?
The number of drives that can fail without data loss.
13. Is RAID 5 better than RAID 6?
RAID 6 offers more protection but less efficiency.
14. Which RAID is best for NAS?
RAID 5 or RAID 6 are common for NAS setups.
15. Is RAID 10 faster than RAID 5?
Yes, especially for write-heavy workloads.
Final Thoughts
The RAID Array Calculator is a powerful, easy-to-use tool for comparing RAID 0, 1, 5, 6, and 10 configurations. Whether you're planning a small NAS or enterprise-grade storage, this tool provides instant clarity on:
- Usable capacity
- Overhead
- Efficiency
- Fault tolerance
Make smarter storage decisions today by calculating before you build.