[azza2110]

You can work this out from structural engineering principals - Euler's theory of column buckling would likely govern the cross sectional area of the legs.

But yes, you're right, building things from wood is such a time-honored technique that it is rare for this to be required. Millions of stools, cabinets, and timber-framed houses have already been successfully built, so there's no need to reinvent the wheel when you can just copy what has been done previously.