RAID Capacity & Rebuild Time Calculator

Quickly estimate usable storage, fault tolerance, and array recovery speed.

Configuration Error: Insufficient drives for the selected RAID level.
Usable Storage 0 TB
Array Overhead 0 TB
Fault Tolerance 0 Drives
Est. Rebuild Time 0 Hours

How RAID Calculations and Rebuild Times Work

Unlocking the true potential of your network-attached storage or server infrastructure requires understanding how different RAID levels distribute data. For instance, RAID 5 requires at least 3 drives and uses the equivalent of one drive for parity, protecting your setup against a single drive failure.

The estimated rebuild time is a crucial metric for system administrators. When a drive fails and is replaced, the controller must reconstruct the missing data based on parity calculations. If you use high-capacity drives (such as 10 TB or larger), the rebuild process can take several hours or even days, during which the remaining drives are under heavy stress.