How do you convert running feet to cubic feet?

Answer 1

"Running feet" is not a common phrase and certainly not mathematical, but I've seen it used to describe lengths of things like timber.

You can't mix linear and volumetric units, but if the "running feet" are of the length of a solid then multiply them by the width and thickness (both also in feet!) of the material to find its volume in cubic feet.

NOTE the conversion so all the linear dimensions are in the same units.

So a 12 ["running"] ft long beam of 6 x 6 inches section will be of

12 x 1/2 x 1/2 feet linearly,

= 3 cubic feet volume.