Is the usable size of a RAIDZ array similar to the usable size of a RAID5 array?

The RAID5 calculation is "(N-1) * S", where S is the size of smallest drive. Since most people use the same sized disk in a RAID5 array, this comes out to be "N-1" for most purposes.

Is RAIDZ also "(N-1) * Smin" ?

Similarly, RAID6 is (N-2) * S. Is the usable size of RAIDZ2 similar to RAID6?