Who runs it
raidcapacitycalc.com is an independent site. It is not linked to any drive, NAS or controller maker, and it does not sell anything.
Contact: [email protected]. If a number looks wrong, please write. Corrections are welcome and fixed quickly.
How the figures are calculated
Capacities use the standard formulas for each RAID level and decimal terabytes, the way drives are labelled. The TiB figure is the same space in binary units, as Windows shows it. Rebuild time is one drive's size divided by the rebuild speed. The read error figure is 1 − e−bits read ÷ error rate, using the worst-case rates drive makers publish.
RAID 50 and RAID 60 are calculated with two spans of equal size. Real controllers, NAS systems and ZFS differ in details such as metadata, reserved space and how they handle read errors, so treat every figure as a planning estimate.