RAID Capacity Calculator
RAID Capacity Results
| RAID Level | Usable Capacity (GB) | Fault Tolerance |
|---|
| RAID | Usable Capacity Formula | Fault Tolerance |
|---|---|---|
| RAID 0 | N × S | None |
| RAID 1 | S (if N=2) | 1 |
| RAID 5 | (N − 1) × S | 1 |
| RAID 6 | (N − 2) × S | 2 |
| RAID 10 | (N ÷ 2) × S | Up to half |
| JBOD | N × S | None |
When planning a storage system, choosing the right RAID (Redundant Array of Independent Disks) configuration can be challenging. Each RAID level offers different trade-offs between storage efficiency, speed, and data protection. That’s where the RAID Capacity Calculator comes in.
This free tool allows users to quickly calculate usable capacity and fault tolerance for various RAID levels (RAID 0, RAID 1, RAID 5, RAID 6, RAID 10, and JBOD). Whether you’re a system administrator, data center engineer, or tech enthusiast, the calculator provides instant insights into how your drives will perform when grouped under different RAID setups.
How to Use the RAID Capacity Calculator (Step-by-Step)
The RAID Capacity Calculator is simple and beginner-friendly. Follow these steps:
- Enter the Number of Drives
- Input how many hard drives or SSDs you plan to use.
- Minimum: 2 drives, Maximum: 24 drives.
- Enter the Drive Size (GB)
- Input the size of each drive in gigabytes.
- Example: 2000 for 2TB drives.
- Select the RAID Level
- Choose from available RAID levels:
- RAID 0 (Striping)
- RAID 1 (Mirroring)
- RAID 5 (Striped with Parity)
- RAID 6 (Double Parity)
- RAID 10 (1+0)
- JBOD (Just a Bunch Of Disks)
- Choose from available RAID levels:
- Click “Calculate”
- The calculator will instantly display the usable capacity and fault tolerance for the chosen RAID level.
- Reset if Needed
- Use the “Reset” button to clear all inputs and start a new calculation.
- Copy or Share Results
- Copy results to your clipboard or share them directly with others.
Practical Example
Let’s say you have 6 drives, each 4TB in size, and you want to configure RAID 5.
- Number of Drives: 6
- Drive Size: 4000 GB
- RAID Level: RAID 5
Click Calculate, and the tool will show:
- Usable Capacity: (6 – 1) × 4000 = 20,000 GB (20 TB)
- Fault Tolerance: 1 drive
This means you’ll get 20TB of usable storage, and the system can survive the failure of 1 drive without data loss.
Key Features of the RAID Capacity Calculator
- ✅ Supports Multiple RAID Levels (0, 1, 5, 6, 10, JBOD)
- ✅ Instant Results with usable storage and fault tolerance values
- ✅ Error Detection for invalid configurations (e.g., RAID 1 requires 2 drives, RAID 10 requires an even number of drives)
- ✅ Copy & Share Options to quickly export results
- ✅ Mobile-Friendly Design that works on desktops, tablets, and smartphones
Benefits of Using the RAID Calculator
- Saves Time: No need to manually compute formulas for different RAID levels.
- Avoids Mistakes: Built-in logic ensures you don’t attempt invalid RAID configurations.
- Helps with Planning: Perfect for IT professionals and storage planners before purchasing drives.
- Educational: Great learning tool for understanding how RAID impacts usable storage.
- Practical for Budgets: Lets you compare RAID levels and see which offers the best balance of performance and redundancy.
Common Use Cases
- Data Center Planning – Estimate usable space before deploying storage servers.
- Home NAS Setup – Plan RAID for Synology, TrueNAS, or Unraid systems.
- Enterprise Storage Design – Compare redundancy and usable space trade-offs.
- Educational Purposes – Teach students about RAID without manual math.
- Pre-Purchase Evaluation – See if your drive setup fits your needs before buying.
Tips for Using the RAID Calculator Effectively
- Always enter the same drive sizes for accurate results (mixed sizes may vary in real-world setups).
- Consider your redundancy needs (RAID 0 has no protection, while RAID 6 allows two failures).
- Use RAID 10 only if you have at least 4 drives and they’re even in number.
- Remember that real-world usable capacity may be slightly lower due to formatting and overhead.
- Use the copy/share feature to quickly share results with your IT team.
RAID Reference Chart
| RAID Level | Usable Capacity Formula | Fault Tolerance |
|---|---|---|
| RAID 0 | N × S | None |
| RAID 1 | S (with 2 drives) | 1 |
| RAID 5 | (N – 1) × S | 1 |
| RAID 6 | (N – 2) × S | 2 |
| RAID 10 | (N ÷ 2) × S | Up to half |
| JBOD | N × S | None |
(N = number of drives, S = drive size)
Frequently Asked Questions (FAQ)
Here are 20 common questions about RAID and the calculator:
1. What is a RAID Capacity Calculator?
It’s a tool that helps you calculate usable storage and fault tolerance for different RAID levels.
2. Do I need to install anything to use it?
No, it’s a web-based tool that works directly in your browser.
3. Which RAID levels are supported?
RAID 0, RAID 1, RAID 5, RAID 6, RAID 10, and JBOD.
4. Can RAID improve performance?
Yes, RAID 0 and RAID 10 provide speed benefits by striping data across drives.
5. Which RAID level is best for data protection?
RAID 6 is very secure because it tolerates up to 2 drive failures.
6. Does RAID replace backups?
No, RAID improves reliability but does not replace backups.
7. Can I use drives of different sizes?
The calculator assumes equal drive sizes. In practice, mixed drives usually default to the smallest drive size.
8. What happens if I choose RAID 1 with more than 2 drives?
The calculator will show an error since RAID 1 requires exactly 2 drives.
9. What’s the main difference between RAID 5 and RAID 6?
RAID 5 tolerates one failure; RAID 6 tolerates two.
10. Is RAID 10 better than RAID 5?
RAID 10 offers faster performance but uses more storage for redundancy.
11. What does JBOD mean?
JBOD stands for “Just a Bunch Of Disks” and simply adds all capacities together without redundancy.
12. Why can’t I select RAID 10 with 3 drives?
RAID 10 requires an even number of drives, minimum 4.
13. Can I use SSDs with RAID?
Yes, SSDs can be used in RAID just like HDDs.
14. Does RAID slow down performance?
Some levels like RAID 5 and RAID 6 may slow write speeds due to parity calculations.
15. What is “fault tolerance”?
It’s the number of drives that can fail without data loss.
16. How accurate are the results?
They’re based on standard RAID formulas but real-world capacity may vary slightly.
17. Can I share results with my team?
Yes, you can copy results or use the share button.
18. Do I need technical knowledge to use this tool?
No, the tool is designed for both beginners and professionals.
19. Is the calculator mobile-friendly?
Yes, it works on smartphones, tablets, and desktops.
20. Why should I use this instead of manual formulas?
Because it’s faster, error-free, and provides instant results.
Conclusion
The RAID Capacity Calculator is an essential tool for anyone designing a storage system. With just a few inputs, you can understand how different RAID levels affect usable storage and fault tolerance. Whether you’re setting up a home NAS or planning enterprise storage, this tool saves time, prevents mistakes, and helps you make better decisions.
👉 Try it out before buying your drives to ensure your RAID setup meets your storage and reliability needs.