Converge Calculator

In the world of data storage and redundancy, understanding how much usable storage you actually have after accounting for parity can be confusing. Whether you’re configuring a NAS, building a RAID setup, or simply planning your storage infrastructure, having a quick way to calculate storage metrics is invaluable.

That’s where our Converge Calculator comes in — a user-friendly online tool designed to compute usable, redundant, and raw storage capacity based on your configuration. With just a few inputs, you’ll have a clear breakdown of how your drives contribute to performance and fault tolerance.

📊 What Is the Converge Calculator?

The Converge Calculator is a web-based utility that helps users calculate three key metrics for parity-based storage systems:

  • Raw Storage: Total capacity across all drives.
  • Usable Storage: The portion of the storage that is available for data.
  • Redundant Storage: The capacity dedicated to parity (used for fault tolerance).

Whether you’re setting up a RAID 5, RAID 6, or custom parity-based system, this calculator will give you an instant insight into your drive configuration.

🔧 How to Use the Converge Calculator (Step-by-Step)

Using the calculator is straightforward. Follow these simple steps:

  1. Enter Total Number of Drives
    • Input the number of drives in your system (must be at least 3).
    • Example: 6 drives.
  2. Enter Drive Size (in TB)
    • Specify the capacity of each drive in terabytes.
    • Example: 4 TB.
  3. Enter Number of Parity Drives
    • This is the number of drives used for redundancy.
    • Example: 2 parity drives (for RAID 6 or dual parity systems).
  4. Click “Calculate”
    • The calculator instantly displays:
      • Usable Storage in TB.
      • Redundant Storage in TB.
      • Raw Storage in TB.
  5. Click “Reset” to start over with new values.

🧮 Example Calculation

Let’s say you have:

  • 6 Drives
  • Each Drive is 4 TB
  • 2 Parity Drives

Calculation:

  • Raw Storage = 6 × 4 TB = 24 TB
  • Redundant Storage = 2 × 4 TB = 8 TB
  • Usable Storage = (6 – 2) × 4 TB = 16 TB

In this setup, you get 16 TB of usable data storage with 8 TB reserved for parity to protect against drive failure.

💡 Why This Tool Matters

Storage planning isn’t just about total capacity. It’s about balancing usable space with fault tolerance. Here’s why the Converge Calculator is essential:

  • Prevents Miscalculations: Avoid overestimating available storage.
  • Helps Optimize RAID Configurations: Especially important for RAID 5, 6, and ZFS-like parity systems.
  • Saves Time: Instant results without needing complex spreadsheets or formulas.
  • Visual Clarity: Helps IT teams explain storage usage to stakeholders or clients.

📦 Real-World Use Cases

Here are some practical applications for using the calculator:

1. NAS Builders & Home Servers

When building a DIY NAS (e.g., using Unraid or TrueNAS), planning capacity is key to avoiding disappointment.

2. Enterprise RAID Planning

System admins can use the calculator to test different configurations before implementing large-scale RAID arrays.

3. Cloud Storage Gateway Configurations

Hybrid systems that use local parity arrays before syncing to the cloud can benefit from capacity planning.

4. Educational Labs

IT instructors can use this tool for classroom demos on RAID and storage management.

📚 Additional Information About Storage Systems

🔁 What Is Parity in Storage?

Parity is a method of adding redundancy by storing calculated data across drives, allowing the system to recover from a drive failure without data loss.

🧩 RAID vs. Non-RAID Storage

  • RAID 5: 1 drive worth of parity.
  • RAID 6: 2 drives worth of parity.
  • JBOD: No parity — all storage is usable but no redundancy.

⚠️ RAID Is Not a Backup

Always remember: RAID improves availability, not data safety. Backups are still necessary.

❓ Frequently Asked Questions (FAQs)

1. What is the Converge Calculator used for?

It helps you calculate usable, redundant, and raw storage based on the number of drives, drive size, and parity drives.

2. What is ‘usable storage’?

The amount of storage available to store your actual data, excluding space used for parity/redundancy.

3. What does ‘redundant storage’ mean?

It’s the portion of your total storage that is reserved for parity — used to recover data in case of drive failure.

4. What is ‘raw storage’?

The total combined capacity of all drives in your array.

5. How many drives do I need to use this tool?

At least 3 drives, since that’s the minimum for most RAID or parity setups.

6. What happens if total drives equal parity drives?

You’ll get an error. Usable storage would be zero, which makes no sense in real configurations.

7. Can this calculator be used for RAID 5 and RAID 6?

Yes! Simply enter 1 parity drive for RAID 5 and 2 for RAID 6.

8. Is this tool suitable for ZFS or Unraid parity systems?

Absolutely. As long as the system uses parity-based redundancy, it applies.

9. Does it work with drives of different sizes?

No, the current version assumes all drives are the same size.

10. Can I calculate storage in GB or MB instead of TB?

You can, but you’ll need to manually convert values to TB before inputting them.

11. What is a parity drive?

A drive that holds calculated information used to restore data from a failed drive.

12. Why is my usable storage less than I expected?

Because parity consumes storage space to provide redundancy.

13. Is RAID 5 still safe to use today?

For large drives, RAID 6 is often preferred due to better fault tolerance.

14. How do I reset the calculator?

Click the “Reset” button to clear all inputs and start fresh.

15. Does the tool store any of my data?

No. All calculations are done locally in your browser — no data is stored or transmitted.

16. Can I embed this calculator in my own site?

Not by default, but you could replicate it using similar JavaScript logic.

17. Can I use this for object-based storage systems?

Not directly — the calculator is designed for parity-based block storage.

18. Does this calculator work on mobile?

Yes, it is fully functional on mobile devices.

19. What happens if I input invalid values?

The tool will show an alert asking you to correct your input.