NAS Capacity Calculator

Project how much usable NAS storage to plan for from current data, growth, and a free-space reserve.

Result

Plan about 8.6 TB of usable NAS storage.

Projected data

6.9 TB

Usable capacity to plan

8.6 TB

That figure is usable storage, not raw drive capacity. RAID redundancy means you will need more raw disk than this. Use the RAID calculator to turn usable capacity into a drive layout. The NAS drive compatibility checker then compares listed form-factor and interface facts for a specific model pair.

RAID Calculator · NAS Drive Compatibility Checker

How this was calculated

Projected data = current data × (1 + annual growth rate)^years. 0% growth is allowed.
Required usable capacity = projected data ÷ (1 − reserve fraction).
GB and TB are decimal manufacturer units (1 TB = 1,000 GB).
The result is usable storage to plan for, not the raw capacity of the drives you will buy.

Limitations

Backup copies are separate and are not included.
Snapshots, versions, and recycle bins can consume additional space.
Filesystem and vendor overhead varies and is not modeled in full.
RAID redundancy changes how much raw disk you need for the same usable capacity.

Related guides

How Much NAS Storage Do I Need?

Calculate the NAS capacity you actually need by accounting for your files, growth, RAID or parity, filesystem overhead, snapshots, and free-space headroom. A worked example shows why raw drive capacity is not the same as usable storage.

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NAS Storage Calculator: How to Estimate Usable Capacity

Estimate NAS capacity from drive count and size by separating raw storage, RAID or parity, filesystem overhead, and free-space headroom. A worked example shows how much space you can realistically plan to use.

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