We have 4 cats (2lbs, 8lbs, 11lbs & 14lbs). There is enough room for them all. The top three platforms are a little small for my 14lb cat but he doesn't seem to mind, he just hangs off, LOL.  We put it in a corner to help make it more sturdy.  We looked all around town before looking online. We needed enough room for all of them at a good price.  I am very happy with the results!