RAID Calculator Online

RAID (short for "Redundant Array of Independent Disks") combines several physical drives into a single logical array to improve fault tolerance, performance, or both at once. Different RAID levels distribute data across disks in different ways. For example, RAID 0 splits data into blocks and writes them in parallel across all drives with no redundancy, RAID 1 fully duplicates data on each drive, and RAID 5 and RAID 6 spread data along with parity information, allowing recovery if one (RAID 5) or even two (RAID 6) drives fail at the same time.

Nested levels such as RAID 10, RAID 50, and RAID 60 combine the strengths of several schemes. RAID 10, for instance, first mirrors pairs of drives and then stripes data across those pairs, delivering high read and write speeds along with fault tolerance, though it requires twice the raw disk space. JBOD (Just a Bunch Of Disks) deserves a separate mention: it simply combines drives into one large volume with no redundancy and no performance gain, making it suitable only for expanding storage capacity where reliability is handled some other way.

The calculator accounts for these differences when computing results: it shows the usable capacity of the RAID array after redundancy overhead, the number of drives that can fail without data loss, and the storage space efficiency as a percentage. This is particularly useful when planning your own NAS storage, database servers, or a home media library, where it helps to understand the tradeoff between reliability, speed, and actual available disk space ahead of time.