About RAID Calculator
Compare raw and usable storage, capacity efficiency, minimum disk count, and disk fault tolerance for common RAID levels.
Check the tool page and Privacy Policy for how this workflow handles your input.
Frequently Asked Questions
No. Filesystem metadata, controller behavior, spare disks, and decimal-versus-binary units can reduce the capacity shown by an operating system.
No. RAID can improve availability after some disk failures, but it does not replace separate, tested backups.
This estimate assumes equal-size disks. Most RAID layouts use only the capacity of the smallest member on every disk.