RAID 5 Calculator – Estimate Usable Storage in Seconds

If you’re setting up a RAID 5 storage array, it’s essential to know how much usable storage space you’ll actually have after redundancy. This is where our RAID 5 Calculator comes in. Whether you’re an IT professional building a server or a small business owner managing your own NAS, this tool simplifies your planning process by delivering instant results based on the number and size of disks you intend to use.

What Is RAID 5?

RAID 5 (Redundant Array of Independent Disks – Level 5) is a commonly used data storage method that combines striping with parity. It offers fault tolerance, meaning your data is still safe even if one disk fails. However, this redundancy comes at a small cost: one of the drives’ capacity is reserved for parity data.

Key Highlights of RAID 5:

Requires at least 3 disks
Offers fault tolerance for one disk failure
Balances performance, storage, and reliability
Common in servers, NAS systems, and business storage setups

Why Use a RAID 5 Calculator?

Planning storage without accurate calculations can lead to poor performance or wasted space. A RAID 5 calculator helps:

Avoid surprises when provisioning storage
Optimize hardware investments
Get quick answers without manual math

Our RAID 5 Calculator eliminates the guesswork by delivering precise usable storage instantly.

How to Use the RAID 5 Calculator (Step-by-Step)

Using this calculator is simple and beginner-friendly. Just follow these steps:

Enter the Number of Disks:
Minimum of 3 disks is required for RAID 5. You can enter any number above that.
Input Disk Size (in GB):
Specify the size of each individual disk in gigabytes.
Choose Output Unit:
Select whether you want the result in GB (Gigabytes) or TB (Terabytes).
Click “Calculate”:
Instantly see the total usable RAID 5 storage after redundancy is applied.
Click “Reset” if you want to enter new values and start fresh.

Example Use Cases

Let’s say you have:

5 disks, each with a 2,000 GB capacity.

Using the calculator:

Input: 5 disks, 2000 GB
Output: (5 – 1) × 2000 = 8000 GB usable, or approximately 7.81 TB

This helps you plan your storage and file organization better.

Who Should Use This Tool?

IT Managers and Sysadmins: For enterprise RAID planning
Small Business Owners: Managing in-house servers or NAS
Home Lab Enthusiasts: DIY NAS or media server setup
Tech Consultants: Quick calculations during client presentations

Benefits of Using Our RAID 5 Calculator

✅ No registration or sign-up required
✅ Instant results
✅ Mobile-friendly and lightweight
✅ Helps avoid costly configuration mistakes
✅ Perfect for RAID 5 beginners and pros alike

Additional RAID 5 Planning Tips

Always use identical disk sizes for optimal performance
RAID 5 is not a backup – combine with cloud or offline backups
If more than one disk fails, all data is lost – use RAID 6 for extra redundancy
Larger RAID arrays can take longer to rebuild

15+ Most Frequently Asked Questions (FAQs)

1. What is RAID 5 used for?

RAID 5 is used for fault-tolerant storage solutions where both performance and data protection are essential.

2. How many disks are required for RAID 5?

A minimum of three disks is required to set up RAID 5.

3. How is usable storage calculated in RAID 5?

Usable storage = (Number of Disks – 1) × Disk Size

4. Does RAID 5 protect against disk failure?

Yes, RAID 5 can tolerate one disk failure without data loss.

5. Can I mix different-sized drives in RAID 5?

Technically yes, but the system will use the smallest drive size for all calculations, wasting the rest.

6. What happens if two disks fail in RAID 5?

You will lose all data. RAID 5 protects against only one disk failure.

7. Is RAID 5 faster than a single disk?

Yes, RAID 5 offers improved read speeds. Write speeds may vary.

8. How reliable is RAID 5?

It’s reliable for read-heavy environments, but rebuilds after disk failure can be slow and risky on large arrays.

9. Is RAID 5 good for home use?

Yes, especially for media servers or backup storage if combined with external backup.

10. Can I expand a RAID 5 array later?

Some systems allow RAID expansion, but it can be complex and may require downtime.

11. What file systems are best for RAID 5?

Common options include NTFS, EXT4, Btrfs, or ZFS, depending on the operating system.

12. What happens during a rebuild?

The array reconstructs the data on a new disk using parity, which can take hours or days depending on size.

13. Is RAID 5 better than RAID 1?

RAID 5 offers more storage efficiency but less redundancy compared to RAID 1 (mirroring).

14. Can SSDs be used in RAID 5?

Yes, but check for wear leveling and write endurance compatibility.

15. What’s the difference between TB and GB in the calculator?

1 TB = 1024 GB. The calculator converts GB to TB when requested.

16. Is there a risk of data corruption with RAID 5?

Yes, especially during rebuilds or power loss. Using enterprise-grade disks and UPS is recommended.

17. Can I use RAID 5 with USB external drives?

It’s not recommended due to slower speeds and reliability issues.

18. Does RAID 5 work on Windows or Linux?

Yes, both Windows (via Storage Spaces or third-party tools) and Linux (via mdadm) support RAID 5.

19. Do I need a RAID controller?

For hardware RAID, yes. Software RAID is possible without one, but performance may vary.

Final Thoughts

If you’re planning to set up a RAID 5 storage system, WorkNSolution’s RAID 5 Calculator is your go-to utility for quick and reliable storage estimations. It ensures you make informed decisions about your storage infrastructure—whether you’re a tech pro or a first-time NAS builder.