RAID capacity calculator
Usable capacity and fault tolerance for RAID 0, 1, 5, 6 and 10.
Runs in your browser. Nothing you type is sent to the server.
About this tool
Choose a RAID level, the number of disks and the size of each disk. The calculator shows usable capacity, the share of raw capacity you keep, and how many disk failures the set can survive. It ignores hot spares, file system overhead and the difference between decimal and binary terabytes.