I never sell by the pile or form a pile. I always stack it 5 high x16 long with 16 to 18'' average splits.
I give an extra foot in height to make up for the short length. No one wants 24'' wood. Max is 18'' so the stack needs to be a little bigger then a standard 24'' stack.
My ricks for a cord of nominal 16" lengths.
4'x24' = cord
5'x20' = cord + a bit
6'x16' = cord + a bit
When selling, I add a bit over the above to be sure it is full measure.