Help with bp tank size vs bp size?

I was wandering my snake tank sizes. I have these plastic tanks with sliding doors, equivalent of Visions or Herpteks, but from a cheaper brand.

The smallest of the three sizes they make is 22,5" wide, 13" high and 22" deep.

Here is a picture of one without the glass doors.

How large bps should be comfortable in this? Subadults should be okay, but I'm not quite sure about adults, especially females.

Other sizes they make are like that one but twice as high, and the largest is both twice as high and twice as wide.

I'd love to get my hands on Vision cages, but nobody seems to be willing to ship them overseas. :(

The general rule of thumb is one square foot of floor space per foot of snake. Given those dimensions it should comfortably fit a snake about 3.5 feet long which is about the size of a male but might be a little small for a female. However, Balls seem to do better in smaller enclosures than other species so it might be okay for a small female.

Thanks a million, that was a new piece of info for me, I've read about a lot of different space requirement stuff but that's a good one to go by. :)

I can house larger females in the largest tanks, I can create more floor space by adding some kind of levels or artificial cliffs etc.

Thanks again!