SOLVED Mirror+Stripe Size Calculator?

[eroji]

Is there a correct way to calculate what my pool size is supposed to be for mirror+stripe configuration? I have 12 drives of 5TB, in set of 2 drive mirrors. I just upgraded 4 of these drives from 4TB to 5TB. The total size of the pool is 20.5TB. For some reason, this just doesn't look right to me.

 

[eroji]

So I completed misunderstood what "available" meant. It was actually 27.2TB, which is more than what I had estimated at 80% usable.