Synology Capacity Calculator

Network Attached Storage (NAS) devices are essential for personal, business, and enterprise data management. Synology NAS devices are popular due to their reliability, flexibility, and powerful storage options. When setting up a NAS, one of the key challenges is estimating how much storage you need and determining the most efficient RAID configuration.

Synology Capacity Calculator

What is a Synology Capacity Calculator?

The calculator is an online tool that helps you determine:

  • Usable storage capacity based on disks and RAID type.
  • Total storage available after redundancy.
  • Maximum storage for your Synology NAS device.
  • Optimal RAID configuration for performance and safety.

By inputting disk sizes, quantity, and RAID type, you can quickly see how much storage will be available for your data while keeping redundancy in mind.

How to Use the Synology Capacity Calculator

  1. Select NAS Model – Choose your Synology NAS device.
  2. Enter Number of Drives – Input the total number of hard drives or SSDs you plan to install.
  3. Specify Drive Capacity – Enter the storage capacity of each disk.
  4. Choose RAID Type – Options include RAID 0, RAID 1, RAID 5, RAID 6, RAID 10, SHR (Synology Hybrid RAID).
  5. Calculate – The tool shows total usable capacity, overhead for redundancy, and potential data protection levels.

This helps you plan your storage efficiently, balancing performance, redundancy, and cost.

Formula Behind the Calculator

The usable capacity of a NAS depends on the RAID type:

  • RAID 0: Usable Capacity = Sum of all disks (no redundancy)
  • RAID 1: Usable Capacity = Capacity of smallest disk (mirrored)
  • RAID 5: Usable Capacity = (N – 1) × Capacity of smallest disk
  • RAID 6: Usable Capacity = (N – 2) × Capacity of smallest disk
  • RAID 10: Usable Capacity = (N / 2) × Capacity of smallest disk (mirrored + striped)
  • SHR: Usable Capacity depends on disks and redundancy (similar to RAID 5/6 but flexible)

Where N = number of drives.

Example Calculations

Example 1: Small RAID 1 Setup

  • Number of Drives: 2
  • Disk Size: 4 TB each
  • RAID Type: RAID 1

Usable Capacity = 4 TB
Redundancy = 50% (one drive mirrors the other)

Example 2: Medium RAID 5 Setup

  • Number of Drives: 4
  • Disk Size: 6 TB each
  • RAID Type: RAID 5

Usable Capacity = (4 – 1) × 6 TB = 18 TB
Redundancy = 6 TB

Example 3: Large SHR Setup

  • Number of Drives: 5
  • Disk Size: 8 TB each
  • RAID Type: SHR (1-disk redundancy)

Usable Capacity = 32 TB (similar to RAID 5 with 5 drives)
Redundancy = 8 TB

Benefits of Using the Synology Capacity Calculator

  • Quickly estimate usable storage for various RAID setups.
  • Helps avoid overspending on unnecessary drives.
  • Ensures data redundancy for protection against drive failures.
  • Allows planning for future expansion.
  • Improves understanding of RAID and SHR configurations.

Additional Insights

  • RAID 0 is high-performance but risky (no redundancy).
  • RAID 1 is best for small setups or critical data mirroring.
  • RAID 5 balances performance, capacity, and redundancy.
  • RAID 6 provides extra redundancy for large arrays.
  • SHR is flexible and ideal for mixed drive sizes.
  • Always leave some free space for snapshots, caching, and system operations.

20 Frequently Asked Questions (FAQs)

1. What is a Synology Capacity Calculator?
It’s a tool to estimate usable storage, RAID efficiency, and redundancy for Synology NAS devices.

2. Can it handle different disk sizes?
Yes, especially when using SHR, which adapts to mixed drive capacities.

3. Does it calculate RAID 5 and 6?
Yes, it supports common RAID configurations including RAID 0, 1, 5, 6, 10, and SHR.

4. What is SHR?
Synology Hybrid RAID, which provides flexible redundancy and easier upgrades.

5. Can it plan for future expansion?
Yes, you can simulate adding drives to see updated capacity.

6. Is RAID necessary for home NAS?
For data protection, yes. RAID prevents data loss from drive failure.

7. How do I calculate usable storage manually?
Use the RAID formulas: RAID 5 = (N – 1) × disk size, RAID 6 = (N – 2) × disk size.

8. Can I use SSDs in Synology NAS?
Yes, SSDs are supported for caching or full storage arrays.

9. Does the calculator account for formatting overhead?
Most calculators provide rough estimates; minor overhead (5–10%) may occur.

10. Can I mix drive sizes in RAID 5?
It’s possible but less efficient; SHR is better for mixed sizes.

11. How does RAID improve performance?
RAID 0 and RAID 10 can increase read/write speed by striping data across disks.

12. What is the difference between RAID 5 and SHR?
RAID 5 requires identical drives; SHR allows mixed sizes with similar redundancy.

13. Can I recover data if a drive fails?
Yes, if using RAID 1, 5, 6, 10, or SHR, data can be recovered after replacing the failed drive.

14. Is SHR recommended for home users?
Yes, it’s flexible and user-friendly for expanding storage.

15. Do I need to use all drive slots?
No, you can start with fewer drives and expand later using SHR.

16. Can I calculate backup storage needs?
Yes, by including secondary NAS or cloud storage, you can plan total capacity.

17. How accurate are the calculations?
They provide close estimates; actual usable space may be slightly lower due to system overhead.

18. Can I use the calculator for enterprise NAS?
Yes, it works for personal, small business, and enterprise Synology NAS devices.

19. Does it account for SSD caching?
Some advanced calculators allow you to include cache in performance estimates.

20. Is it free to use online?
Yes, Synology and third-party calculators are typically free.

Conclusion

A Synology Capacity Calculator is an essential planning tool for anyone setting up a NAS. It ensures you maximize usable storage, maintain redundancy, and plan for future growth. By understanding RAID, SHR, and total capacity, you can make informed decisions for both home and business storage needs.