A Full Cord measures 4' high x 8' long x 4' deep and contains 128 cubic feet of wood.
 

Most Seasoned Hardwoods will average 2 tons for each full cord of wood.  Be careful when ordering from a dealer by weight - you may be overpaying!.  It is illegal to sell firewood in any other measure than a full cord or fraction of a cord (per the Ohio Department of Agriculture).
 

A standard 8 foot pickup truck bed can not hold a full cord of wood without side rails.  Again, be sure you get what you pay for!